View source for Graphite

{{Short description|Crystalline form of carbon}}
{{hatnote group|
{{other uses}}
{{distinguish|Graphene}}
}}
{{Use American English|date=November 2021}}
{{Infobox mineral
| name = Graphite
| category = [[Native mineral]]
| boxwidth = 
| boxbgcolor = 
| image = Graphite-233436.jpg
| imagesize = 170px
| caption = Graphite specimen
| formula = [[Carbon|C]]
| IMAsymbol   = Gr<ref>{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|journal=Mineralogical Magazine|volume=85|issue=3|pages=291–320|doi=10.1180/mgm.2021.43|bibcode=2021MinM...85..291W|s2cid=235729616|doi-access=free}}</ref>
| strunz = 1.CB.05a
| system = [[Hexagonal crystal system|Hexagonal]] or [[Rhombohedral crystal system|Rhombohedral]]
| class = Dihexagonal dipyramidal (6/mmm) <br/>[[Hermann–Mauguin notation]]: (6/m 2/m 2/m)
| symmetry = ''P''6<sub>3</sub>''mc'' (buckled) ''P''6<sub>3</sub>/''mmc'' (flat)
| unit cell = ''a'' = 2.461, ''c'' = 6.708&nbsp;[Å]; ''Z''&nbsp;=&nbsp;4
| molweight = 
| color = Iron-black to steel-gray; deep blue in transmitted light 
| habit = Tabular, six-sided [[Foliation (geology)|foliated]] masses, granular to compacted masses
| twinning = Present
| cleavage = Basal – perfect on {0001}
| fracture = Flaky, otherwise rough when not on cleavage
| tenacity = Flexible non-elastic, sectile
| mohs = 1–2
| luster = Metallic, earthy
| refractive = 
| opticalprop = Uniaxial (−)
| birefringence = 
| pleochroism = Strong
| streak = Black
| gravity = 1.9–2.3
| density = 2.09–2.23 g/cm<sup>3</sup>
| fusibility = 
| diagnostic = 
| solubility = Soluble in molten [[nickel]], warm [[chlorosulfuric acid]]<ref>[http://phys.org/news194418761.html Liquid method: pure graphene production]. Phys.org (May 30, 2010).</ref>
| diaphaneity = Opaque, transparent only in extremely thin flakes
| other = strongly anisotropic, conducts electricity, greasy feel, readily marks
| references = <ref>[http://www.mindat.org/min-1740.html Graphite]. Mindat.org.</ref><ref>[http://www.webmineral.com/data/Graphite.shtml Graphite]. Webmineral.com.</ref><ref name=HBM>{{cite book|editor1=Anthony, John W. |editor2=Bideaux, Richard A. |editor3=Bladh, Kenneth W. |editor4=Nichols, Monte C. |title= Handbook of Mineralogy|publisher= Mineralogical Society of America|place= Chantilly, VA |chapter-url=http://rruff.info/doclib/hom/graphite.pdf |archive-url=https://web.archive.org/web/20131004224223/http://rruff.info/doclib/hom/graphite.pdf |archive-date=2013-10-04 |url-status=live|chapter=Graphite|isbn=978-0-9622097-0-3 |series=Vol. I (Elements, Sulfides, Sulfosalts)|year=1990}}</ref>
}}

'''Graphite''' ({{IPAc-en|ˈ|ɡ|r|æ|f|aɪ|t}}) is a [[Crystallinity|crystalline]] allotrope (form) of the element [[carbon]]. It consists of many stacked [[Layered materials|layers]] of [[graphene]], typically in excess of hundreds of layers. Graphite occurs naturally and is the most stable form of carbon under [[standard conditions]].  Synthetic and natural graphite are consumed on a large scale (1.3{{nbsp}}million metric tons per year in 2022) for uses in many critical industries including [[refractories]] (50%), [[lithium-ion batteries]] (18%), [[foundries]] (10%), and [[lubricants]] (5%), among others (17%).<ref>{{cite web | url=https://www.statista.com/statistics/719592/global-distribution-of-graphite-consumption-by-end-use/ | title=Graphite global consumption share by end use and type }}</ref> Graphite converts to [[diamond]] under extremely high pressure and temperature. Graphite's low cost, thermal and chemical inertness and characteristic conductivity of heat and electricity finds numerous applications in high energy and high temperature processes.<ref name="USGS_PP1802J">{{cite journal | doi=10.3133/pp1802J | title=Graphite | date=2017 | last1=Robinson | first1=Gilpin R. | last2=Hammarstrom | first2=Jane M. | last3=Olson | first3=Donald W. | journal=USGS Report | page=3 | bibcode=2017usgs.rept....3R | editor-first1=Klaus J. | editor-first2=John H. | editor-first3=Robert R. | editor-first4=Dwight C. | editor-last1=Schulz | editor-last2=Deyoung | editor-last3=Seal | editor-last4=Bradley }}{{source-attribution}}</ref>
{{toclimit|3}}

== Types and varieties ==
Graphite can occur naturally or be produced synthetically. Natural graphite is obtained from naturally occurring geologic deposits and synthetic graphite is produced through human activity.<ref name="USGS_PP1802J"/><ref name="BanekEtAl_GR1">{{cite journal|vauthors=Banek NA, Abele DT, McKenzie, Jr KR, Wagner MJ|date=2018|title=Sustainable Conversion of Lignocellulose to High-Purity, Highly Crystalline Flake Potato Graphite|journal=ACS Sustainable Chemistry and Engineering|volume=6|issue=10|pages=13199–13207|doi=10.1021/acssuschemeng.8b02799|bibcode=2018ASCE....613199B |osti=1475076 }}</ref>

=== Natural ===
Graphite occurs naturally in [[ore]]s that can be classified as either ''amorphous'' (microcrystalline) or ''crystalline'' (flake or lump/chip) which is determined by the ore [[Polymorphism (materials science)|morphology]], [[crystallinity]], and [[grain size]].<ref name="USGS_PP1802J"/> All naturally occurring graphite deposits are formed from the [[metamorphism]] of [[carbonaceous]] [[sedimentary rocks]], and the ore type is due to its geologic setting. [[Coal]] that has been thermally metamorphosed is the typical source of amorphous graphite. Crystalline flake graphite is mined from [[carbonaceous]] [[metamorphic rocks]], while lump or chip graphite is mined from veins which occur in high-grade [[metamorphic]] regions.<ref name="USGS_PP1802J"/> There are serious negative environmental impacts to graphite mining.

=== Synthetic===
Synthetic graphite has high purity and is usually produced by the thermal [[graphitization]] of [[hydrocarbon]] materials at temperatures in excess of 2,100&nbsp;°C, most commonly through the [[Acheson process]].<ref name="USGS_PP1802J"/><ref name="Acheson_1906">{{cite patent |country=US |number=836355 |title=Production of Graphite |pubdate=1906-11-20 |fdate=1906-10-22 |inventor=Acheson, E. G.}}</ref> The high temperatures are maintained for weeks, and are required not only to form the graphite from the precursor carbons but also to [[vaporize]] any impurities that may be present, including hydrogen, nitrogen, sulfur, organics, and metals.<ref name="USGS_PP1802J"/> The resulting synthetic graphite is highly pure{{emdash}}in excess of 99.9% C purity{{emdash}}but typically has lower density, conductivity and a higher porosity than its natural equivalent.<ref name="USGS_PP1802J"/> Synthetic graphite can be formed into very large (centimeter-scale) flakes while maintaining its high purity, unlike almost all sources of natural graphite.<ref name="USGS_PP1802J"/> Synthetic graphite can also be formed by other methods including by [[chemical vapor deposition]] from hydrocarbons at temperatures above {{convert|2500|K|C}}, by decomposition of thermally unstable [[carbide]]s, or by [[crystallization]] from metal melts [[supersaturated]] with [[carbon]].<ref>{{cite book |doi=10.1016/B978-008044463-5/50023-6 |chapter=Production and Reference Material |title=Activated Carbon |date=2006 |last1=Marsh |first1=Harry |last2=Rodríguez-Reinoso |first2=Francisco |pages=454–508 |isbn=978-0-08-044463-5 }}</ref>

=== Research ===
Research and development efforts continue into new methods for the industrial production of graphite for a variety of applications, including [[lithium-ion batteries]], refractories, and foundries, among others. Significant work has been done on graphitizing of traditionally non-graphitizable carbons. A company in [[New Zealand]] utilizes forestry waste to produce what they have termed 'biographite' through a process referred to as thermo-catalytic [[graphitization]].<ref>{{Cite web|url=https://www.euronews.com/green/2024/02/26/cars-powered-by-woodchips-biographite-makes-ev-batteries-sustainable|title=Batteries made from woodchips could clean up the EV industry|date=February 26, 2024|website=euronews}}</ref><ref>{{Cite web|url=https://www.batterytechonline.com/materials/carbonscape-s-renewable-biographite-anode-material-ready-to-scale|title=CarbonScape Renewable Biographite Anode Material Ready to Scale|website=www.batterytechonline.com}}</ref> Another group in the [[United States]] uses a method referred to as [[photocatalytic]] graphitization to produce highly crystalline highly pure graphite for lithium-ion batteries and other applications from a variety of carbon sources.<ref name="BanekEtAl_GR1"/><ref name="BanekEtAl_GR2">{{cite journal|vauthors=Banek NA, McKenzie, Jr KR, Abele DT, Wagner MJ |date= 2022 |title=Sustainable conversion of biomass to rationally designed lithium-ion battery graphite |journal=Scientific Reports|volume= 12 |issue= 1 |article-number= 8080 |doi= 10.1038/s41598-022-11853-x |pmid= 35577817 |bibcode= 2022NatSR..12.8080B |pmc= 9110727 }}</ref>

==Natural ==
===Occurrence===
Graphite occurs in [[metamorphic rock]]s as a result of the [[reduction (chemistry)|reduction]] of [[Sedimentary rock|sedimentary]] carbon compounds during [[metamorphism]]. It also occurs in [[igneous rock]]s and in [[meteorite]]s.<ref name=HBM/> [[Mineral|Minerals]] associated with graphite include [[quartz]], [[calcite]], [[mica]]s and [[tourmaline]]. The principal export sources of mined graphite are, in order of tonnage, [[China]], [[Mexico]], [[Canada]], [[Brazil]], and [[Madagascar]].<ref name="MineralsDatabase">{{cite web
  | title = Graphite
  | work = Minerals Database
  | publisher = Minerals Education Coalition
  | date = 2018
  | url = https://mineralseducationcoalition.org/minerals-database/graphite/
  | access-date = 9 December 2018}}</ref> Significant unexploited graphite resources also exist in [[Colombia]]'s [[Cordillera Central (Colombia)|Cordillera Central]] in the form of graphite-bearing [[schist]]s.<ref>{{Cite journal |title=Is the Central Cordillera of Colombia a potential source of graphite?: Implications for the energy transition in Colombia |journal=[[Andean Geology]] |url=http://www.andeangeology.cl/index.php/revista1/article/view/V51n2-3728/html |last1=Bustamante |first1=C. |issue=2 |volume=51 |pages=413–420 |last2=Cardona |first2=A. |date=2024 |doi=10.5027/andgeoV51n2-3728|doi-access=free |bibcode=2024AndGe..51..413B }}</ref>

In [[meteorite]]s, graphite occurs with [[troilite]] and [[silicate mineral]]s.<ref name=HBM/> Small graphitic crystals in [[meteoritic iron]] are called [[cliftonite]].<ref name=Brit/> Some microscopic grains have distinctive [[Isotope|isotopic]] compositions, indicating that they were formed before the [[Solar System]].<ref>{{cite book |last1=Lugaro |first1=Maria |author-link1=Maria Lugaro |title=Stardust From Meteorites: An Introduction To Presolar Grains |date=2005 |publisher=World Scientific |isbn=978-981-4481-37-3 |pages=14, 154–157}}</ref> They are one of about 12 known types of minerals that predate the Solar System and have also been detected in [[molecular cloud]]s. These minerals were formed in the [[ejecta]] when [[supernova]]e exploded or low to intermediate-sized stars expelled their outer envelopes late in their lives. Graphite may be the second or third oldest mineral in the Universe.<ref>{{cite journal |last1=Hazen |first1=R. M. |last2=Downs |first2=R. T. |last3=Kah |first3=L. |last4=Sverjensky |first4=D. |title=Carbon Mineral Evolution |journal=Reviews in Mineralogy and Geochemistry |date=13 February 2013 |volume=75 |issue=1 |pages=79–107 |doi=10.2138/rmg.2013.75.4 |bibcode=2013RvMG...75...79H }}</ref><ref>{{cite journal |last1=McCoy |first1=T. J. |title=Mineralogical Evolution of Meteorites |journal=Elements |date=22 February 2010 |volume=6 |issue=1 |pages=19–23 |doi=10.2113/gselements.6.1.19|bibcode=2010Eleme...6...19M }}</ref>

===Structure===
Graphite consists of sheets of trigonal planar carbon.<ref>{{cite book |last1=Delhaes |first1=Pierre |chapter=Polymorphism of carbon |editor-last1=Delhaes |editor-first1=Pierre |title=Graphite and precursors |date=2000 |publisher=Gordon & Breach |isbn=978-90-5699-228-6|pages=1–24}}</ref><ref>{{cite book |last1=Pierson |first1=Hugh O. |title=Handbook of carbon, graphite, diamond, and fullerenes: properties, processing, and applications |date=2012 |publisher=Noyes Publications |isbn=978-0-8155-1739-9 |pages=40–41}}</ref> The individual layers are called [[graphene]]. In each layer, each carbon atom is bonded to three other atoms forming a continuous layer of sp<sup>2</sup> bonded carbon hexagons, like a [[honeycomb lattice]] with a bond length of 0.142&nbsp;nm, and the distance between planes is 0.335&nbsp;nm.<ref>{{cite book |title= Graphite and Precursors |author= Delhaes, P. |publisher= CRC Press |year= 2001 |url= https://books.google.com/books?id=7p2pgNOWPbEC&pg=PA146 |isbn= 978-90-5699-228-6}}</ref> Bonding between layers is relatively weak [[van der Waals force|van der Waals bonds]], which allows the graphene-like layers to be easily separated and to glide past each other.<ref>{{cite journal |last1=Chung |first1=D. D. L. |title=Review Graphite |journal=Journal of Materials Science |date=2002 |volume=37 |issue=8 |pages=1475–1489 |doi=10.1023/A:1014915307738 |s2cid=189839788 }}</ref> Electrical conductivity perpendicular to the layers is consequently about 1000 times lower.<ref>{{Cite book |last=Pierson |first=Hugh O. |title=Handbook of carbon, graphite, diamond, and fullerenes: properties, processing, and applications |date=1993 |publisher=Noyes Publications |isbn=0-8155-1739-4 |location=Park Ridge, N.J. |oclc=49708274}}</ref>

There are two allotropic forms called ''alpha'' ([[Hexagonal crystal family|hexagonal]]) and ''beta'' ([[Rhombohedral crystal system|rhombohedral]]), differing in terms of the stacking of the graphene layers: stacking in alpha graphite is ABA, as opposed to ABC stacking in the energetically less stable beta graphite. Rhombohedral graphite cannot occur in pure form.<ref name=Gold/> Natural graphite, or commercial natural graphite, contains 5 to 15% rhombohedral graphite<ref name=rhombo>{{Cite journal |last1=Latychevskaia |first1=Tataiana |last2=Son |first2=Seok-Kyun |last3=Yang |first3=Yaping |last4=Chancellor |first4=Dale |last5=Brown |first5=Michael |last6=Ozdemir |first6=Servet |last7=Madan |first7=Ivan |last8=Berruto |first8=Gabriele |last9=Carbone |first9=Fabrizio  |last10=Mishchenko |first10=Artem |last11=Novoselov |first11=Kostya |date=2019-08-17 |title=Stacking transition in rhombohedral graphite |journal=Frontiers of Physics |volume=14 |issue=1 |at=13608 |doi=10.1007/s11467-018-0867-y  |arxiv=1908.06284 |bibcode=2019FrPhy..1413608L |s2cid=125322808}}</ref> and this may be due to intensive milling.<ref>{{cite journal |last1=E. Fitzer |display-authors=etal|title=Recommended terminology for the description of carbon as a solid (IUPAC Recommendations 1995) |journal=Pure and Applied Chemistry |date=1995 |volume=67 |issue=3 |pages=473–506 |doi=10.1351/pac199567030473 |bibcode=1995PApCh..67..473F |url=https://www.degruyter.com/document/doi/10.1351/pac199567030473/html}}</ref> The alpha form can be converted to the beta form through shear forces, and the beta form reverts to the alpha form when it is heated to 1300&nbsp;°C for four hours.<ref name=rhombo/><ref name=Gold>{{GoldBookRef |file=R05385 |title=Rhombohedral graphite}}</ref>

<gallery perrow="6">
File:Graphite ambient STM.jpg|[[Scanning tunneling microscope]] image of graphite surface
File:Graphite-layers-side-3D-balls.png|Side view of ABA layer stacking
File:Graphite-layers-top-3D-balls.png|Plane view of layer stacking
File:Graphite-unit-cell-3D-balls.png|Alpha graphite's [[unit cell]] 
</gallery>

===Thermodynamics===
[[File:Carbon basic phase diagram.png|thumb|upright=1.15|Theoretically predicted [[phase diagram]] of carbon]]
The equilibrium pressure and temperature conditions for a transition between graphite and diamond is well established theoretically and experimentally. The pressure changes linearly between {{val|1.7|ul=GPa}} at {{val|0|u=K}} and {{val|12|u=GPa}} at {{val|5000|u=K}} (the diamond/graphite/liquid [[triple point]]).<ref name=Bundy>{{cite journal |last1=Bundy |first1=P. |last2=Bassett |first2=W. A. |last3=Weathers |first3=M. S. |last4=Hemley |first4=R. J. |last5=Mao |first5=H. K. |last6=Goncharov |first6=A. F. |title=The pressure-temperature phase and transformation diagram for carbon; updated through 1994 |journal=Carbon |date=1996 |volume=34 |issue=2 |pages=141–153 |doi=10.1016/0008-6223(96)00170-4|bibcode=1996Carbo..34..141B }}</ref><ref>{{cite book |first1=C. X. |last1=Wang |first2=G. W. |last2=Yang |chapter=Thermodynamic and kinetic approaches of diamond and related nanomaterials formed by laser ablation in liquid |editor-last1=Yang |editor-first1=Guowei |title=Laser ablation in liquids: principles and applications in the preparation of nanomaterials |date=2012 |publisher=Pan Stanford Pub |isbn=978-981-4241-52-6 |pages=164–165}}</ref>
However, the phases have a wide region about this line where they can coexist. At [[Standard temperature and pressure|normal temperature and pressure]], {{convert|20|C|K}} and {{convert|1|atm|MPa}}, the stable phase of carbon is graphite, but diamond is [[metastable]] and its rate of conversion to graphite is negligible.<ref name=ChemThermo>{{cite book |last1=Rock |first1=Peter A. |title=Chemical Thermodynamics |date=1983 |publisher=University Science Books |isbn=978-1-891389-32-0 |pages=257–260}}</ref> However, at temperatures above about {{val|4500|u=K}}, diamond rapidly converts to graphite. Rapid conversion of graphite to diamond requires pressures well above the equilibrium line: at {{val|2000|u=K}}, a pressure of {{val|35|u=GPa}} is needed.<ref name=Bundy/>

===Other properties===
[[File:Graphite-pV.svg|thumb|upright=1.15|Molar volume against pressure at room temperature]]
The [[Acoustics|acoustic]] and [[Heat|thermal]] properties of graphite are highly [[anisotropic]], since [[phonons]] propagate quickly along the tightly bound planes, but are slower to travel from one plane to another. Graphite's high thermal stability and electrical and thermal conductivity facilitate its widespread use as electrodes and refractories in high temperature material processing applications. However, in oxygen-containing atmospheres graphite readily oxidizes to form [[carbon dioxide]] at temperatures of 700&nbsp;°C and above.<ref>{{cite journal |last1=Hanaor |first1=Dorian |last2=Michelazzi |first2=Marco |last3=Chenu |first3=Jeremy |last4=Leonelli |first4=Cristina |last5=Sorrell |first5=Charles C. |title=The effects of firing conditions on the properties of electrophoretically deposited titanium dioxide films on graphite substrates |journal=Journal of the European Ceramic Society |date=December 2011 |volume=31 |issue=15 |pages=2877–2885 |doi=10.1016/j.jeurceramsoc.2011.07.007 |arxiv=1303.2757 }}</ref>

Graphite is an [[electrical conductor]], hence useful in such applications as [[arc lamp]] [[electrode]]s. It can conduct electricity due to the vast [[electron]] [[delocalization]] within the carbon layers (a phenomenon called [[aromaticity]]). These valence electrons are free to move, so are able to conduct electricity. However, the electricity is primarily conducted within the plane of the layers. The conductive properties of powdered graphite<ref>{{cite journal |last1=Deprez |first1=N. |last2=McLachlan |first2=D. S. |year=1988 |title=The analysis of the electrical conductivity of graphite conductivity of graphite powders during compaction |journal=[[Journal of Physics D: Applied Physics]] |volume=21 |issue=1 |pages=101–107 |doi=10.1088/0022-3727/21/1/015 |bibcode=1988JPhD...21..101D |s2cid=250886376 }}</ref> allow its use as pressure sensor in [[carbon microphone]]s.

Graphite and graphite powder are valued in industrial applications for their self-lubricating and dry [[lubricant|lubricating]] properties. However, the use of graphite is limited by its tendency to facilitate [[pitting corrosion]] in some [[stainless steel]],<ref>[http://steel.keytometals.com/Articles/Art160.htm Galvanic Corrosion] {{Webarchive |url=https://web.archive.org/web/20090310033053/http://steel.keytometals.com/Articles/Art160.htm |date=2009-03-10 }}. keytometals.com</ref><ref>{{cite web |url= http://metals.lincdigital.com.au/files/ASM_Tech_Notes/TN7-0506-Galvanic%20Corrosion.pdf |archive-url= https://web.archive.org/web/20090227143601/http://metals.lincdigital.com.au/files/ASM_Tech_Notes/TN7-0506-Galvanic%20Corrosion.pdf |archive-date= 2009-02-27 |title= ASM Tech Notes – TN7-0506 – Galvanic Corrosion |work= Atlas Specialty Metals}}</ref> and to promote [[galvanic corrosion]] between dissimilar metals (due to its electrical conductivity). It is also corrosive to aluminium in the presence of moisture. For this reason, the [[US Air Force]] banned its use as a lubricant in aluminium aircraft,<ref>Jones, Rick (USAF-Retired) [http://www.graflex.org/speed-graphic/lubricants.html Better Lubricants than Graphite]. graflex.org</ref> and discouraged its use in aluminium-containing automatic weapons.<ref>{{cite web |url = http://gojackarmy.blogspot.com/2005/09/weapons-lubricant-in-desert.html  |archive-url = https://web.archive.org/web/20071015045426/http://gojackarmy.blogspot.com/2005/09/weapons-lubricant-in-desert.html |archive-date = 2007-10-15 |date = September 16, 2005 |title = Weapons Lubricant in the Desert |access-date = 2009-06-06}}</ref> Even graphite [[pencil]] marks on aluminium parts may facilitate corrosion.<ref>{{cite web |url = http://7faq.com/owbase/ow.asp?GoodEngineeringPractice%2FCorrosion |title = Good Engineering Practice/Corrosion |publisher = Lotus Seven Club |date = 9 April 2003 |archive-url = https://web.archive.org/web/20090916035828/http://7faq.com/owbase/ow.asp?GoodEngineeringPractice%2FCorrosion |archive-date = 16 September 2009}}</ref> Another high-temperature lubricant, [[boron nitride|hexagonal boron nitride]], has the same molecular structure as graphite. It is sometimes called ''white graphite'', due to its similar properties.

When a large number of crystallographic defects bind its planes together, graphite loses its lubrication properties and becomes what is known as [[pyrolytic graphite]]. It is also highly anisotropic, and [[diamagnetic]], thus it will float in mid-air above a strong magnet. (If it is made in a fluidized bed at 1000–1300&nbsp;°C then it is isotropic turbostratic, and is used in blood-contacting devices like mechanical heart valves and is called [[pyrolytic carbon]], and is not diamagnetic. Pyrolytic graphite and pyrolytic carbon are often confused but are very different materials.<ref>{{cite book |last1=Marsh |first1=Harry |last2=Reinoso |first2=Francisco Rodríguez |title=Activated carbon |date=2007 |publisher=Elsevier |isbn=978-0-08-045596-9 |pages=497–498 |edition=1st}}</ref>)

For a long time graphite has been considered to be hydrophobic. However, recent studies using highly ordered pyrolytic graphite have shown that freshly clean graphite is hydrophilic ([[contact angle]] of 70° approximately), and it becomes hydrophobic (contact angle of 95° approximately) due to airborne pollutants (hydrocarbons) present in the atmosphere.<ref name="Martinez-Martin-2013">{{cite journal |last1=Martinez-Martin |first1=David |last2=Longuinhos |first2=Raphael |last3=Izquierdo |first3=Jesus G. |last4=Marele |first4=Antonela |last5=Alexandre |first5=Simone S. |last6=Jaafar |first6=Miriam |last7=Gómez-Rodríguez |first7=Jose M. |last8=Bañares |first8=Luis |last9=Soler |first9=Jose M. |last10=Gomez-Herrero |first10=Julio |title=Atmospheric contaminants on graphitic surfaces |journal=Carbon |date=September 2013 |volume=61 |pages=33–39 |doi=10.1016/j.carbon.2013.04.056 |bibcode=2013Carbo..61...33M }}</ref><ref>{{cite journal |last1=Li |first1=Zhiting |last2=Wang |first2=Yongjin |last3=Kozbial |first3=Andrew |last4=Shenoy |first4=Ganesh |last5=Zhou |first5=Feng |last6=McGinley |first6=Rebecca |last7=Ireland |first7=Patrick |last8=Morganstein |first8=Brittni |last9=Kunkel |first9=Alyssa |last10=Surwade |first10=Sumedh P. |last11=Li |first11=Lei |last12=Liu |first12=Haitao |title=Effect of airborne contaminants on the wettability of supported graphene and graphite |journal=Nature Materials |date=October 2013 |volume=12 |issue=10 |pages=925–931 |doi=10.1038/nmat3709 |pmid=23872731 |bibcode=2013NatMa..12..925L }}</ref> Those contaminants also alter the electric equipotential surface of graphite by creating domains with potential differences of up to 200 mV as measured with [[Kelvin probe force microscope|kelvin probe force microscopy]].<ref name="Martinez-Martin-2013" /> Such contaminants can be desorbed by increasing the temperature of graphite to approximately 50&nbsp;°C or higher.<ref name="Martinez-Martin-2013" />

Natural and crystalline graphites are not often used in pure form as structural materials, due to their shear-planes, brittleness, and inconsistent mechanical properties.

==History of use==
[[File:Kimmirut Graphite.jpg|thumb|Graphite plates and sheets, 10–15&nbsp;cm high; mineral specimen from [[Kimmirut]], Canada]]
In the 4th millennium [[BCE]], during the [[Neolithic]] Age in southeastern Europe, the [[Boian culture|Marița culture]] used graphite in a ceramic paint for decorating [[pottery]].<ref name="Cambridge">{{Cite book|title=The Cambridge ancient history, Volume 3, Part 1 |first=John |last=Boardman |chapter=The Neolithic-Eneolithic Period |date=1924 |pages=31–32 |publisher=Cambridge University Press |isbn=((978-0521224963)) |chapter-url=http://home.lu.lv/~harijs/Macibu%20materiali%20,teksti/Cambrige%20Ancient%20History/Cambridge%20Ancient%20History%203.1.%20Balkans,%20Middle%20East%20&%20Aegean%20World%2010-8th%20c.pdf |archive-url=https://web.archive.org/web/20130225042733/http://home.lu.lv/~harijs/Macibu%20materiali%20%2Cteksti/Cambrige%20Ancient%20History/Cambridge%20Ancient%20History%203.1.%20Balkans%2C%20Middle%20East%20%26%20Aegean%20World%2010-8th%20c.pdf |archive-date=25 February 2013 }}</ref>

Sometime before 1565 (some sources say as early as 1500), an enormous deposit of graphite was discovered on the approach to [[Grey Knotts]] from the hamlet of [[Seathwaite, Allerdale|Seathwaite]] in [[Borrowdale|Borrowdale parish]], [[Cumbria]], [[England]], which the locals found useful for marking sheep.<ref name="norgate">{{cite web
|url=http://www.geog.port.ac.uk/webmap/thelakes/html/lgaz/lk00976.htm
|title=Old Cumbria Gazetteer, black lead mine, Seathwaite
|year=2008
|author=Norgate, Martin |author2=Norgate, Jean |publisher=Geography Department, Portsmouth University
|access-date=2008-05-19}}</ref><ref name="wainwright_western">{{cite book|title=A Pictorial Guide to the Lakeland Fells, Western Fells
|author=Wainwright, Alfred |url=https://books.google.com/books?id=BbYQmWu8OfEC&pg=RA1-PT16
|year=2005
|isbn=978-0-7112-2460-5|publisher=Frances Lincoln|location=London
}}</ref> During the reign of [[Elizabeth I]] (1558–1603), Borrowdale graphite was used as a [[refractory]] material to line molds for cannonballs, resulting in rounder, smoother balls that could be fired farther, contributing to the strength of the English navy. This particular deposit of graphite was extremely pure and soft, and could easily be cut into sticks. Because of its military importance, this unique mine and its production were strictly controlled by the Crown.<ref>{{cite journal | title=Account of the Black Lead Mine in Borrowdale | journal =Memoir of the Manchester Literary and Philosophical Society, Ser. 2 | volume = 3| date = 1819 | url = https://books.google.com/books?id=Cpj3h3tcnSsC |access-date=6 April 2025 | first = Jonathan | last = Otley | page =168-175}}</ref><ref>{{cite book|title=The Statutes at Large: From the ... Year of the Reign of ... to the ... Year of the Reign of ..|url=https://books.google.com/books?id=eaRFAAAAcAAJ&pg=PA415|year=1764|page=415}}</ref>

During the 19th century, graphite's uses greatly expanded to include stove polish, lubricants, paints, crucibles, foundry facings, and [[pencil]]s, a major factor in the expansion of educational tools during the first great rise of education for the masses.  The British Empire controlled most of the world's production (especially from Ceylon), but production from Austrian, German, and American deposits expanded by mid-century.  For example, the Dixon Crucible Company of Jersey City, New Jersey, founded by [[Joseph Dixon (inventor)|Joseph Dixon]] and partner [[Orestes Cleveland]] in 1845, opened mines in the Lake Ticonderoga district of New York, built a processing plant there, and a factory to manufacture pencils, crucibles and other products in New Jersey, described in the ''Engineering & Mining Journal'' 21 December 1878.  The Dixon pencil is still in production.<ref>{{cite web|url=http://www.dixonusa.com/history.html|title = History|archive-date = 7 April 2018|archive-url = https://web.archive.org/web/20180407053901/http://www.dixonusa.com/history.html|website= Dixon Ticonderoga Company }}</ref>
[[File:“Orgy of the Growl Devils “ “Graphited Wood Grease” 1908 ad - Electric railway review (IA electricrailwayr19amer) (page 50 crop).jpg|thumb|upright|Graphited Wood Grease 1908 ad in the Electric Railway Review]]
The beginnings of the revolutionary [[froth flotation]] process are associated with graphite mining.  Included in the ''E&MJ'' article on the Dixon Crucible Company is a sketch of the "floating tanks" used in the age-old process of extracting graphite.  Because graphite is so light, the mix of graphite and waste was sent through a final series of water tanks where a cleaner graphite "floated" off, which left waste to drop out.  In an 1877 patent, the two brothers Bessel (Adolph and August) of Dresden, Germany, took this "floating" process a step further and added a small amount of oil to the tanks and boiled the mix – an agitation or frothing step – to collect the graphite, the first steps toward the future flotation process.  Adolph Bessel received the Wohler Medal for the patented process that upgraded the recovery of graphite to 90% from the German deposit.  In 1977, the German Society of Mining Engineers and Metallurgists organized a special symposium dedicated to their discovery and, thus, the 100th anniversary of flotation.<ref name = nguyen>{{cite book|last1=Nguyen|first1=Ahn|title=Colloidal Science of Flotation|date=2003|isbn= 978-0-8247-4782-4 |pages=11|publisher=CRC Press }}</ref>

In the United States, in 1885, Hezekiah Bradford of Philadelphia patented a similar process, but it is uncertain if his process was used successfully in the nearby graphite deposits of Chester County, Pennsylvania, a major producer by the 1890s.  The Bessel process was limited in use, primarily because of the abundant cleaner deposits found around the globe, which needed not much more than hand-sorting to gather the pure graphite.  The state of the art, {{circa|1900}}, is described in the Canadian Department of Mines report on graphite mines and mining when Canadian deposits began to become important producers of graphite.<ref name = nguyen/><ref>{{cite book|last1=Cirkel|first1=Fritz|title=Graphite its Properties, Occurrence, Refining and Uses|date=1907|publisher=Canadian Department of Mines|location=Ottawa|page=passim|url= https://books.google.com/books?id=IQXOAAAAMAAJ&q=Bessel+graphite&pg=PA218 |access-date=6 April 2018}}</ref>

=== Other names {{anchor|Plumbago}} ===
[[File:Crane’s Servants Friend series no. 3.jpg|thumb|upright|Advert for Crane's Black Lead, c. 1905]]
Historically, graphite was called '''black lead''' or '''plumbago'''.<ref name=Brit/><ref>{{Cite book
| series = Spons' Workshop Receipts Vol. II: Dyeing to Japanning
| publisher = Spon
| title = Electro-Plating on Non-Metallic Substances
| year = 1921
| page = 132
}}</ref> Plumbago was commonly used in its [[crystal habit#Massive|massive]] mineral form. Both of these names arise from confusion with the similar-appearing [[lead]] ores, particularly [[galena]]. The Latin word for lead, ''[[plumbum]]'', gave its name to the English term for this grey metallic-sheened mineral and even to the leadworts or [[plumbago]]s, plants with flowers that resemble this colour.

The term ''black lead'' usually refers to a powdered or processed graphite, matte black in color.

[[Abraham Gottlob Werner]] coined the name ''graphite'' ("writing stone") in 1789. He attempted to clear up the confusion between molybdena, plumbago and black lead after [[Carl Wilhelm Scheele]] in 1778 proved that these were at least three different minerals. Scheele's analysis showed that the chemical compounds [[molybdenum sulfide]] ([[molybdenite]]), [[lead(II) sulfide]] ([[galena]]) and graphite were three different soft black minerals.<ref>{{cite journal | doi = 10.1111/j.1467-968X.1908.tb00513.x | title = V.— the Meanings and Synonyms of Plumbago | year = 1908 | last1 = Evans | first1 = John W. | journal = Transactions of the Philological Society | volume = 26 | issue = 2 | pages = 133–179| url = https://zenodo.org/record/2111957 }}</ref><ref>{{cite book|author= Widenmann, Johann Friedrich Wilhelm |title= Handbuch des oryktognostischen Theils der Mineralogie: Mit einer Farbentabelle und einer Kupfertafel|url= https://books.google.com/books?id=9QxQAAAAcAAJ&pg=PA653|year= 1794|publisher=Crusius|page= 653}}
</ref><ref>
{{cite journal
| author = Scheele, C. W. K.
| title = Versuche mit Wasserbley; Molybdaena 
| journal = Svenska Vetensk. Academ. Handlingar
| page = 238
| year = 1779
| volume = 40
| url = http://gdz.sub.uni-goettingen.de/dms/load/img/?PPN=PPN324352840_0040
}}
</ref>

==Uses==
Natural graphite is mostly used for refractories, batteries, steelmaking, expanded graphite, brake linings, foundry facings, and lubricants.<ref name=usgs/>

===Refractories===
The use of graphite as a [[refractory]] (heat-resistant) material began before 1900 with graphite [[crucible]]s used to hold molten metal; this is now a minor part of [[Refractory|refractories]]. In the mid-1980s, the carbon-[[magnesite]] brick became important, and a bit later the alumina-graphite shape. {{As of | 2017}} the order of importance is: alumina-graphite shapes, carbon-magnesite brick, Monolithics (gunning and ramming mixes), and then crucibles.

Crucibles began using very large flake graphite, and carbon-magnesite bricks requiring not quite so large flake graphite; for these and others there is now much more flexibility in the size of flake required, and amorphous graphite is no longer restricted to low-end refractories. Alumina-graphite shapes are used as continuous casting ware, such as nozzles and troughs, to convey the molten steel from ladle to Mold, and carbon magnesite bricks line steel converters and electric-arc furnaces to withstand extreme temperatures. Graphite blocks are also used in parts of [[blast furnace]] linings<ref>{{cite journal |last1=Almeida |first1=Bruno Vidal de |last2=Neves |first2=Elton Silva |last3=Silva |first3=Sidiney Nascimento |last4=Vernilli Junior |first4=Fernando |title=Blast Furnace Hearth Lining: Post Mortem Analysis |journal=Materials Research |date=15 May 2017 |volume=20 |issue=3 |pages=814–818 |doi=10.1590/1980-5373-mr-2016-0875|doi-access=free }}</ref> where the high thermal conductivity of the graphite is critical to ensuring adequate cooling of the bottom and hearth of the furnace.<ref>{{cite journal |last1=Li |first1=Yiwei |last2=Li |first2=Yawei |last3=Sang |first3=Shaobai |last4=Chen |first4=Xilai |last5=Zhao |first5=Lei |last6=Li |first6=Yuanming |last7=Li |first7=Shushiting jing |title=Preparation of Ceramic-Bonded Carbon Block for Blast Furnace |journal=Metallurgical and Materials Transactions A |date=January 2014 |volume=45 |issue=1 |pages=477–481 |doi=10.1007/s11661-013-1976-4|bibcode=2014MMTA...45..477L |s2cid=137571156 }}</ref> High-purity monolithics are often used as a continuous furnace lining instead of carbon-magnesite bricks.

The US and European refractories industry had a crisis in 2000–2003, with an indifferent market for steel and a declining refractory consumption per [[tonne]] of steel underlying firm buyouts and many plant closures.{{citation needed|date=January 2017}} Many of the plant closures resulted from the acquisition of Harbison-Walker Refractories by [[RHI AG]] and some plants had their equipment auctioned off. Since much of the lost capacity was for carbon-magnesite brick, graphite consumption within the refractories area moved towards alumina-graphite shapes and Monolithics, and away from the brick. The major source of carbon-magnesite brick is now China. Almost all of the above refractories are used to make steel and account for 75% of refractory consumption; the rest is used by a variety of industries, such as cement.

According to the [[United States Geological Survey|USGS]], US natural graphite consumption in refractories comprised 12,500 tonnes in 2010.<ref name=usgs/>

===Batteries===
The use of graphite in batteries has increased since the 1970s. Natural and synthetic graphite are used as an [[anode]] material to construct [[electrode]]s in major battery technologies.<ref>{{cite web | url=https://www.targray.com/li-ion-battery/anode-materials/graphite | title =Graphite Anode Materials | author =Targray | publisher=[[Targray]] | date =August 27, 2020}}</ref>

Graphite is the "predominant anode material used today in lithium-ion batteries".<ref>{{cite journal |last1=Zhang |first1=Hao |last2=Yang |first2=Yang |last3=Ren |first3=Dongsheng |last4=Wang |first4=Li |last5=He |first5=Xiangming |title=Graphite as anode materials: Fundamental mechanism, recent progress and advances |journal=Energy Storage Materials |date=April 2021 |volume=36 |pages=147–170 |doi=10.1016/j.ensm.2020.12.027 |bibcode=2021EneSM..36..147Z }}</ref> Electric-vehicle (EV) batteries contain four basic components: anode, cathode, electrolyte, and separator. While there is much focus on the cathode materials{{emdash}}lithium, nickel, cobalt, manganese, etc., the anode material used in virtually all EV batteries is graphite.<ref>{{Cite web |url=https://electrek.co/2022/06/09/ev-batteries-need-graphite-heres-whats-forecast-for-the-vital-minerals-supply/ |title=EV batteries need graphite – here's what's forecast for supply |website=Electrek}}</ref>

The demand for batteries, primarily [[Nickel–metal hydride battery|nickel–metal hydride]] and [[lithium-ion batteries]], caused a growth in demand for graphite in the late 1980s and early 1990s – a growth driven by portable electronics, such as portable [[CD player]]s and [[power tool]]s. [[Laptop]]s, [[mobile phone]]s, [[tablet computer|tablet]]s, and smartphone products have increased the demand for batteries. Electric-vehicle batteries are anticipated to increase graphite demand. As an example, a lithium-ion battery in a fully electric [[Nissan Leaf]] contains nearly 40&nbsp;kg of graphite.{{citation needed|date=November 2022}}

Radioactive graphite removed from nuclear reactors has been investigated as a source of electricity for low-power applications. This waste is rich in [[carbon-14]], which emits electrons through [[beta decay]], so it could potentially be used as the basis for a [[betavoltaic device]]. This concept is known as the [[diamond battery]].

===Steelmaking===
Natural graphite in [[steelmaking]] mostly goes into raising the carbon content in molten steel; it can also serve to lubricate the dies used to extrude hot steel. Carbon additives face competitive pricing from alternatives such as synthetic graphite powder, petroleum coke, and other forms of carbon. A carbon raiser is added to increase the carbon content of the steel to a specified level. An estimate based on [[USGS]]'s graphite consumption statistics indicates that [[steelmaker]]s in the US used 10,500 tonnes in this fashion in 2005.<ref name=usgs/>

===Brake linings===
Natural amorphous and fine flake graphite are used in brake linings or [[brake shoes]] for heavier (nonautomotive) vehicles, and became important with the need to substitute for [[asbestos]]. This use has been important for quite some time, but nonasbestos organic (NAO) compositions are beginning to reduce graphite's market share. A brake-lining industry shake-out with some plant closures has not been beneficial, nor has an indifferent automotive market. According to the [[USGS]], US natural graphite consumption in brake linings was 6,510 tonnes in 2005.<ref name=usgs/>

===Foundry facings and lubricants===
A foundry-facing mold wash is a water-based paint of amorphous or fine flake graphite. Painting the inside of a mold with it and letting it dry leaves a fine graphite coat that will ease the separation of the object cast after the hot metal has cooled. Graphite [[lubricants]] are specialty items for use at very high or very low temperatures, as forging die lubricant, an antiseize agent, a gear lubricant for mining machinery, and to lubricate locks. Having low-grit graphite, or even better, no-grit graphite (ultra high purity), is highly desirable. It can be used as a dry powder, in water or oil, or as colloidal graphite (a permanent suspension in a liquid). An estimate based on [[USGS]] graphite consumption statistics indicates that 2,200 tonnes were used in this fashion in 2005.<ref name=usgs/>  Metal can also be impregnated into graphite to create a self-lubricating alloy for application in extreme conditions, such as bearings for machines exposed to high or low temperatures.<ref>{{Cite web|url=https://www.foundrymag.com/feature/graphitemetal-alloy-extends-material-life-high-temperature-processes|title=Graphite/Metal Alloy Extends Material Life in High-Temperature Processes|date=2004-06-04|website=Foundry Management & Technology|access-date=2019-06-20}}</ref>

===Everyday use===

====Pencils====
[[File:Pencils hb.jpg|Graphite pencils|thumb|alt=Graphite pencils]]
The ability to leave marks on paper and other objects gave graphite its name, given in 1789 by German mineralogist [[Abraham Gottlob Werner]]. It stems from ''γράφειν ("graphein")'', meaning ''to write'' or ''draw'' in [[Ancient Greek]].<ref name="Brit">[https://www.britannica.com/EBchecked/topic/242042/graphite graphite]. Encyclopædia Britannica Online.</ref><ref>{{OEtymD|graphite}}</ref>

From the 16th century, all pencils were made with leads of English natural graphite, but modern pencil lead is most commonly a mix of powdered graphite and clay; it was invented by [[Nicolas-Jacques Conté]] in 1795.<ref>{{cite web | url=http://pubs.acs.org/cen/whatstuff/print/7942sci4.html | title =Pencils & Pencil Lead | author =Ritter, Steve | publisher=[[American Chemical Society]] | date =October 15, 2001}}</ref><ref>{{cite web | url=http://lrs.ed.uiuc.edu/students/kzage/ithistory.html | title=The History of the Pencil | publisher=[[University of Illinois at Urbana–Champaign]] | access-date=2013-02-15 | archive-url=https://web.archive.org/web/20150317005153/http://lrs.ed.uiuc.edu/students/kzage/ithistory.html | archive-date=2015-03-17 }}</ref> It is chemically unrelated to the metal [[lead]], whose ores had a similar appearance, hence the continuation of the name. '''Plumbago''' is another older term for natural graphite used for [[drawing]], typically as a lump of the mineral without a wood casing. The term [[plumbago drawing]] is normally restricted to 17th and 18th-century works, mostly portraits.

Today, pencils are still a small but significant market for natural graphite. Around 7% of the 1.1&nbsp;million tonnes produced in 2011 was used to make pencils.<ref name="galaxycapital">{{cite web | url =http://www.galaxycapitalcorp.com/sites/default/files/110720%20-%20Electric%20Graphite%20-%20Initiating%20Coverage.pdf | title =Electric Graphite Growing Demand From Electric Vehicles & Mobile Electronics | publisher =galaxycapitalcorp.com | date =July 20, 2011 | access-date =February 15, 2013 | archive-date =October 4, 2013 | archive-url =https://web.archive.org/web/20131004215128/http://www.galaxycapitalcorp.com/sites/default/files/110720%20-%20Electric%20Graphite%20-%20Initiating%20Coverage.pdf }}</ref> Low-quality amorphous graphite is used and sourced mainly from China.<ref name=usgs/>

In art, graphite is typically used to create detailed and precise drawings, as it allows for a wide range of values (light to dark) to be achieved. It can also be used to create softer, more subtle lines and shading. Graphite is popular among artists because it is easy to control, easy to erase, and produces a clean, professional look. It is also relatively inexpensive and widely available. Many artists use graphite in conjunction with other media, such as charcoal or ink, to create a range of effects and textures in their work.<ref>{{cite web | url=https://www.sybariscollection.com/art-technique-graphite-medium/ | title = ART TECHNIQUE-GRAPHITE AS A MEDIUM | author =Not known | publisher=[[Sybaris]] | date =January 29, 2018}}</ref> Graphite of various hardness or softness results in different qualities and tones when used as an [[artistic medium]].<ref name="SBTCModule6">{{cite web|title=Module 6: Media for 2-D Art|url=http://www.saylor.org/site/wp-content/uploads/2011/12/Module-6.pdf |archive-url=https://web.archive.org/web/20120809171125/http://www.saylor.org/site/wp-content/uploads/2011/12/Module-6.pdf |archive-date=2012-08-09 |url-status=live|publisher=Saylor.org|access-date=2 April 2012}}</ref>

====Pinewood derby====
Graphite is probably the most-used lubricant in [[Pinewood derby|pinewood derbies]].<ref>{{cite web | url=https://www.pinewoodderbycars.com/Top-5-Speed-Tips-for-Your-Pinewood-Derby-Car-a/277.htm | title=Top 5 Speed Tips for Your Pinewood Derby Car | publisher=S&W Crafts Mfg. | access-date=July 28, 2022 }}</ref>

===Other uses===
Natural graphite has found uses in [[Zinc–carbon battery|zinc-carbon batteries]], [[electric motor]] brushes, and various specialized applications. Railroads would often mix powdered graphite with [[waste oil]] or linseed oil to create a heat-resistant protective coating for the exposed portions of a steam locomotive's boiler, such as the [[smokebox]] or lower part of the [[firebox (steam engine)|firebox]].<ref>[http://list.nwhs.org/pipermail/nw-modeling-list/Week-of-Mon-20080623/002828.html True color/appearance of the "Graphite, or Smokebox colors]. List.nwhs.org. Retrieved on 2013-04-15.</ref> The [[Scope soldering iron]] uses a graphite tip as its heating element.

===Expanded graphite===
Expanded graphite is made by immersing natural flake graphite in a bath of [[chromic acid]], then concentrated [[sulfuric acid]], which forces the crystal lattice planes apart, thus expanding the graphite. The expanded graphite can be used to make graphite foil or used directly as a "hot top" compound to insulate molten metal in a ladle or red-hot steel ingots and decrease heat loss, or as [[firestop]]s fitted around a [[fire door]] or in sheet metal collars surrounding plastic pipe (during a fire, the graphite expands and chars to resist fire penetration and spread), or to make high-performance gasket material for high-temperature use. After being made into graphite foil, the foil is machined and assembled into the bipolar plates in [[fuel cells]].
The foil is made into heat sinks for [[laptop computers]] which keeps them cool while saving weight, and is made into a foil laminate that can be used in valve packings or made into gaskets. Old-style packings are now a minor member of this grouping: fine flake graphite in oils or greases for uses requiring heat resistance. A GAN estimate of current US natural graphite consumption in this end-use is 7,500&nbsp;tonnes.<ref name=usgs/>

===Intercalated graphite===
{{main|Graphite intercalation compound}}
[[Image:CaC6structure.jpg|thumb|Structure of CaC<sub>6</sub>]]
Graphite forms [[graphite intercalation compound|intercalation compounds]] with some metals and small molecules. In these compounds, the host molecule or atom gets "sandwiched" between the graphite layers, resulting in a type of compound with variable stoichiometry. A prominent example of an intercalation compound is potassium graphite, denoted by the formula KC<sub>8</sub>. Some graphite intercalation compounds are [[superconductors]]. The highest transition temperature (by June 2009) ''T''<sub>c</sub> = 11.5&nbsp;K is achieved in CaC<sub>6</sub>, and it further increases under applied pressure (15.1&nbsp;K at 8&nbsp;GPa).<ref name="cac6">{{cite journal|pmc=5099629|author1=Emery, Nicolas |author2=Hérold, Claire |author3=Marêché, Jean-François |author4=Lagrange, Philippe |title =Synthesis and superconducting properties of CaC<sub>6</sub>| journal = Sci. Technol. Adv. Mater.|volume = 9| issue = 4|year =2008| article-number =044102|doi = 10.1088/1468-6996/9/4/044102| bibcode=2008STAdM...9d4102E | pmid=27878015}}</ref>  Graphite's ability to intercalate lithium ions without significant damage from swelling is what makes it the dominant anode material in lithium-ion batteries.

==Mining, beneficiation, and milling==
[[File:Naturalis Biodiversity Center - Museum - Exhibition Nature theatre 08 - Graphite, large stone.jpg|thumb|Large graphite specimen. [[Naturalis Biodiversity Center]], [[Leiden]], Netherlands.]]
[[Image:2005graphite.PNG|thumb|upright=1.5|Graphite output in 2005]]
[[File:World graphite reserves and mine production 2022.png|thumb|World graphite reserves and mine production in 2022]]
Graphite is mined by both [[open-pit mining|open pit]] and underground methods. Graphite usually needs [[beneficiation]]. This may be carried out by hand-picking the pieces of gangue (rock) and hand-screening the product or by crushing the rock and floating out the graphite. Beneficiation by flotation encounters the difficulty that graphite is very soft and "marks" (coats) the particles of [[gangue]]. This makes the "marked" gangue particles float off with the graphite, yielding impure concentrate. There are two ways of obtaining a commercial concentrate or product: repeated regrinding and floating (up to seven times) to purify the concentrate, or by acid leaching (dissolving) the gangue with [[hydrofluoric acid]] (for a silicate gangue) or [[hydrochloric acid]] (for a carbonate gangue).{{cn|date=March 2025}}
 
In milling, the incoming graphite products and concentrates can be ground before being classified (sized or screened), with the coarser flake size fractions (below 8 mesh, 8–20 mesh, 20–50 mesh) carefully preserved, and then the carbon contents are determined. Some standard blends can be prepared from the different fractions, each with a certain flake size distribution and carbon content. Custom blends can also be made for individual customers who want a certain flake size distribution and carbon content. If flake size is unimportant, the concentrate can be ground more freely. Typical end products include a fine powder for use as a slurry in [[oil drilling]] and coatings for [[foundry]] molds, carbon raiser in the [[steel]] industry (Synthetic graphite powder and powdered petroleum coke can also be used as carbon raiser). Environmental impacts from graphite mills consist of air pollution including fine particulate exposure of workers and also [[soil contamination]] from powder spillages leading to [[Heavy metals|heavy metal]] contamination of soil.{{cn|date=March 2025}}

According to the [[United States Geological Survey]] (USGS), [[World Productions|world production]] of natural graphite in 2016 was 1,200,000 [[tonne]]s, of which the following major exporters are: [[China]] (780,000&nbsp;t), [[India]] (170,000&nbsp;t), [[Brazil]] (80,000&nbsp;t), [[Turkey]] (32,000&nbsp;t) and [[North Korea]] (6,000&nbsp;t).<ref>{{Cite web|publisher = USGS|url=https://minerals.usgs.gov/minerals/pubs/mcs/2017/mcs2017.pdf |archive-url=https://web.archive.org/web/20170209215134/https://minerals.usgs.gov/minerals/pubs/mcs/2017/mcs2017.pdf |archive-date=2017-02-09 |url-status=live |title=Mineral Commodity Summaries 2020|website=National Minerals Information Center}}</ref> Graphite is not currently mined in the [[United States]], but there are many historical mine sites including ones in Alabama, Montana, and in the [[Adirondacks]] of NY.<ref>{{Cite web|url=https://timbitsblog.wordpress.com/2015/03/24/wonder-5-graphite-mines-boom-town|title=Wonder 5: Graphite Mines – Boom Town|date=24 March 2015 }}</ref>  [[Westwater Resources]] is in the development stages of creating a pilot plant for their Coosa Graphite Mine near [[Sylacauga, Alabama]].<ref>{{Cite news|url=https://www.sylacauganews.com/local/westwater-resources-acquires-alabama-graphite|title=Westwater Resources acquires Alabama Graphite|date=2018-05-16|author=Jeremy Law|access-date=2020-02-22|language=en-US}}</ref> U.S. production of synthetic graphite in 2010 was 134,000&nbsp;t valued at $1.07&nbsp;billion.<ref name="usgs">{{cite web|publisher=USGS|url=https://minerals.usgs.gov/minerals/pubs/commodity/graphite/|title=Graphite Statistics and Information|access-date=2009-09-09}}</ref>

=== Occupational safety ===

Potential [[health effect]]s include: 
*[[Inhalation]]: No inhalation hazard in manufactured and shipped state. Dust and fumes generated from the material can enter the body by inhalation. High concentrations of dust and fumes may irritate the throat and respiratory system and cause coughing. Frequent inhalation of fume/dust over a long period of time increases the risk of developing lung diseases. Prolonged and repeated overexposure to dust can lead to [[pneumoconiosis]]. Pre-existing pulmonary disorders, such as [[emphysema]], may possibly be aggravated by prolonged exposure to high concentrations of graphite dusts.
*Eye contact: Dust in the eyes will cause irritation. Exposed may experience eye tearing, redness, and discomfort.
*Skin contact: Under normal conditions of intended use, this material does not pose a risk to health. Dust may irritate skin.
*[[Ingestion]]: Not relevant, due to the form of the product in its manufactured and shipped state. However, ingestion of dusts generated during working operations may cause nausea and vomiting.
*Potential physical / chemical effects: Bulk material is non-combustible. The material may form dust and can accumulate electrostatic charges, which may cause an [[Electric spark|electrical spark]] (ignition source). High dust levels may create potential for explosion.

====United States====
The [[Occupational Safety and Health Administration]] (OSHA) has set the legal limit ([[permissible exposure limit]]) for graphite exposure in the workplace as a time weighted average (TWA) of 15{{nbsp}}million particles per cubic foot (1.5&nbsp;mg/m<sup>3</sup>) over an 8-hour workday. The [[National Institute for Occupational Safety and Health]] (NIOSH) has set a [[recommended exposure limit]] (REL) of TWA 2.5&nbsp;mg/m<sup>3</sup> respirable dust over an 8-hour workday. At levels of 1250&nbsp;mg/m<sup>3</sup>, graphite is [[IDLH|immediately dangerous to life and health]].<ref>{{Cite web|title = CDC – NIOSH Pocket Guide to Chemical Hazards – Graphite (natural)|url = https://www.cdc.gov/niosh/npg/npgd0306.html|website = www.cdc.gov|access-date = 2015-11-03}}</ref>

== Recycling ==
The most common way of recycling graphite occurs when synthetic graphite electrodes are either manufactured and pieces are cut off or lathe turnings are discarded for reuse, or the electrode (or other materials) are used all the way down to the electrode holder. A new electrode replaces the old one, but a sizeable piece of the old electrode remains. This is crushed and sized, and the resulting graphite powder is mostly used to raise the carbon content of molten steel.

Graphite-containing [[Refractory|refractories]] are sometimes also recycled, but often are not due to their low graphite content: the largest-volume items, such as carbon-magnesite bricks that contain only 15–25% graphite, usually contain too little graphite to be worthwhile to recycle. However, some recycled carbon–magnesite brick is used as the basis for furnace-repair materials, and also crushed carbon–magnesite brick is used in slag conditioners.

While [[crucible]]s have a high graphite content, the volume of crucibles used and then recycled is very small.

A high-quality flake graphite product that closely resembles natural flake graphite can be made from steelmaking kish. Kish is a large-volume near-molten waste skimmed from the molten iron feed to a basic oxygen furnace and consists of a mix of graphite (precipitated out of the supersaturated iron), lime-rich slag, and some iron. The iron is recycled on-site, leaving a mixture of graphite and slag. The best recovery process uses hydraulic classification (which utilizes a flow of water to separate minerals by specific gravity: graphite is light and settles nearly last) to get a 70% graphite rough concentrate. [[Leaching (chemical science)|Leaching]] this concentrate with [[hydrochloric acid]] gives a 95% graphite product with a flake size ranging from 10 [[Mesh (scale)|mesh]] (2&nbsp;mm) down.
==History of synthetic graphite==

===Invention of a production process===
In 1893, Charles Street of Le Carbone discovered a process for making artificial graphite. In the mid-1890s, [[Edward Goodrich Acheson]] (1856–1931) accidentally invented another way to produce synthetic graphite after synthesizing [[Silicon carbide|carborundum]] (also called silicon carbide). He discovered that overheating carborundum, as opposed to pure carbon, produced almost pure graphite. While studying the effects of high temperature on carborundum, he had found that [[silicon]] vaporizes at about {{cvt|4150|C|F}}, leaving the carbon behind in graphitic carbon. This graphite became valuable as a lubricant.<ref name=Brit/>

Acheson's technique for producing silicon carbide and graphite is named the [[Acheson process]]. In 1896, Acheson received a patent for his method of synthesizing graphite,<ref>Acheson, E. G. "Manufacture of Graphite", {{US Patent|568323}}, issued September 29, 1896.</ref> and in 1897 started commercial production.<ref name=Brit/> The Acheson Graphite Co. was formed in 1899.

Synthetic graphite can also be prepared from polyimide and then commercialized.<ref>{{cite journal |last1=Kato |first1=Tomofumi |last2=Yamada |first2=Yasuhiro |last3=Nishikawa |first3=Yasushi |last4=Ishikawa |first4=Hiroki |last5=Sato |first5=Satoshi |title=Carbonization mechanisms of polyimide: Methodology to analyze carbon materials with nitrogen, oxygen, pentagons, and heptagons |journal=Carbon |date=June 2021 |volume=178 |pages=58–80 |doi=10.1016/j.carbon.2021.02.090 |bibcode=2021Carbo.178...58K }}</ref><ref>{{cite journal |last1=Kato |first1=Tomofumi |last2=Yamada |first2=Yasuhiro |last3=Nishikawa |first3=Yasushi |last4=Otomo |first4=Toshiya |last5=Sato |first5=Hayato |last6=Sato |first6=Satoshi |title=Origins of peaks of graphitic and pyrrolic nitrogen in N1s X-ray photoelectron spectra of carbon materials: quaternary nitrogen, tertiary amine, or secondary amine? |journal=Journal of Materials Science |date=October 2021 |volume=56 |issue=28 |pages=15798–15811 |doi=10.1007/s10853-021-06283-5 |bibcode=2021JMatS..5615798K }}</ref>

===Scientific research===

[[Highly oriented pyrolytic graphite]] (HOPG) is the highest-quality synthetic form of graphite. It is used in scientific research, in particular, as a length standard for the calibration of [[scanning probe microscope]]s.<ref name="automatic1998">{{cite journal |last1=Lapshin |first1=Rostislav V. |title=Automatic lateral calibration of tunneling microscope scanners |journal=Review of Scientific Instruments |date=1 September 1998 |volume=69 |issue=9 |pages=3268–3276 |doi=10.1063/1.1149091 |bibcode=1998RScI...69.3268L }}</ref><ref name="real2019">{{cite journal |last1=Lapshin |first1=Rostislav V. |title=Drift-insensitive distributed calibration of probe microscope scanner in nanometer range: Real mode |journal=Applied Surface Science |date=March 2019 |volume=470 |pages=1122–1129 |doi=10.1016/j.apsusc.2018.10.149 |arxiv=1501.06679 |bibcode=2019ApSS..470.1122L }}</ref>

===Electrodes===
Graphite [[electrode]]s carry the electricity that melts [[scrap iron]] and steel, and sometimes [[direct-reduced iron]] (DRI), in [[electric arc furnace]]s, which are the vast majority of [[steel furnace]]s. They are made from [[petroleum coke]] after it is mixed with [[coal tar pitch]]. They are extruded and shaped, then baked to [[carbonize]] the [[binder (material)|binder]] (pitch). This is finally graphitized by heating it to temperatures approaching {{cvt|3000|C|F}}, at which the carbon atoms arrange into graphite. They can vary in size up to {{cvt|3.5|m|0}} long and {{cvt|75|cm|0}} in diameter. An increasing proportion{{as of?|date=September 2023}} of global [[steel]] is made using electric arc furnaces, and the electric arc furnace itself is becoming more efficient, making more steel per tonne of electrode. An estimate based on [[USGS]] data indicates that graphite electrode consumption was {{cvt|197000|MT|ST|abbr=off}} in 2005.<ref name=usgs/>

Electrolytic [[aluminium smelting]] also uses graphitic carbon electrodes. On a much smaller scale, synthetic graphite electrodes are used in [[electrical discharge machining]] (EDM), commonly to make [[injection mold]]s for [[plastic]]s.<ref name="Pierson 1993 p. ">{{cite book | last=Pierson | first=Hugh O. | title=Handbook of Carbon, Graphite, Diamonds and Fullerenes: Properties, Processing and Applications | publisher=Noyes Publications | date=1993 | isbn=0-8155-1339-9 | ol=8048799M }}</ref>

===Powder and scrap===
The powder is made by heating powdered [[petroleum coke]] above the temperature of graphitization, sometimes with minor modifications. The graphite scrap comes from pieces of unusable electrode material (in the manufacturing stage or after use) and lathe turnings, usually after crushing and sizing. Most synthetic graphite powder goes to carbon raising in steel (competing with natural graphite), with some used in batteries and brake linings. According to the [[United States Geographical Survey]], US synthetic graphite powder and scrap production were {{cvt|95000|MT}} in 2001 (latest data).<ref name=usgs/>

It is possible to create battery-grade graphite by recycling the numerous fines from battery production. The process involves spray drying the fines over petroleum pitch with a binder and cross-linking agent, then drying them.<ref>{{Cite journal |last1=Abrego-Martinez |first1=Juan Carlos |last2=Wang |first2=Youling |last3=Vanpeene |first3=Victor |last4=Roué |first4=Lionel |date=2023-06-05 |title=From waste graphite fines to revalorized anode material for Li-ion batteries |url=https://www.sciencedirect.com/science/article/abs/pii/S0008622323002397 |journal=Carbon |volume=209 |article-number=118004 |doi=10.1016/j.carbon.2023.118004 |bibcode=2023Carbo.20918004A |issn=0008-6223|url-access=subscription }}</ref>

===Neutron moderator===
{{main|Nuclear graphite}}
Special grades of synthetic graphite also find use as a matrix and [[neutron moderator]] within [[nuclear reactor]]s. Its low [[neutron cross-section]] also recommends it for use in proposed [[fusion reactor]]s. Care must be taken that reactor-grade graphite is free of neutron absorbing materials such as [[boron]], widely used as the seed electrode in commercial graphite deposition systems – this caused the failure of the Germans' [[World War II]] graphite-based nuclear reactors. Since they could not isolate the difficulty they were forced to use far more expensive [[heavy water]] moderators. Graphite used for nuclear reactors is often referred to as [[nuclear graphite]]. [[Herbert G. MacPherson]], a Berkeley trained physicist at  National Carbon, a division of Union Carbide, was key in confirming a conjecture of Leo Szilard that boron impurities even in "pure" graphite were responsible for a neutron absorption cross-section in graphite that compromised U-235 chain reactions. McPherson was aware of the presence of impurities in graphite because, with the use of Technicolor in cinematography, the spectra of graphite electrode arcs used in movie projectors required impurities to enhance emission of light in the red region to display warmer skin tones on the screen. Thus, had it not been for color movies, chances are that the first sustained natural U chain reaction would have required a heavy water moderated reactor.<ref name="Figure11" >{{cite book | last = Weinberg | first = Alvin M. | title = The First Nuclear Era| publisher = American Institute of Physics | place = New York, N.Y.|year = 1994 |at=Figure 11| isbn =  978-1-56396-358-2}}</ref>

===Other uses===
[[carbon (fiber)|Graphite (carbon) fiber]] and [[carbon nanotube]]s are also used in [[carbon fiber reinforced plastic]]s, and in heat-resistant composites such as [[reinforced carbon-carbon]] (RCC). Commercial structures made from carbon fiber graphite composites include [[fishing rod]]s, golf club shafts, bicycle frames, sports car body panels, the fuselage of the [[Boeing 787 Dreamliner]] and [[Pool (cue sports)|pool]] [[cue sticks]] and have been successfully employed in [[reinforced concrete]]. The mechanical properties of carbon fiber graphite-reinforced plastic composites and grey [[cast iron]] are strongly influenced by the role of graphite in these materials. In this context, the term "(100%) graphite" is often loosely used to refer to a pure mixture of carbon reinforcement and [[resin]], while the term "composite" is used for [[composite materials]] with additional ingredients.<ref>Cooper, Jeff. [http://tennis.about.com/od/tennisracquetsfaq/f/faqracquets42.htm What is the best material for a tennis racquet?] {{Webarchive|url=https://web.archive.org/web/20110707075415/http://tennis.about.com/od/tennisracquetsfaq/f/faqracquets42.htm |date=2011-07-07 }}. tennis.about.com</ref>

Modern [[smokeless powder]] is coated in graphite to prevent the buildup of [[static charge]].

Graphite has been used in at least three [[radar absorbent material]]s. It was mixed with rubber in Sumpf and Schornsteinfeger, which were used on [[U-boat]] [[Submarine snorkel|snorkels]] to reduce their [[radar cross section]]. It was also used in tiles on early [[F-117 Nighthawk]] stealth strike fighters.

Graphite composites are used as absorber for high-energy particles, for example in the [[Large Hadron Collider]] beam dump.<ref>{{Cite web|url=https://www.symmetrymagazine.org/sites/default/files/legacy/pdfs/200712/protecting_the_lhc.pdf |archive-url=https://web.archive.org/web/20150910023817/http://www.symmetrymagazine.org/sites/default/files/legacy/pdfs/200712/protecting_the_lhc.pdf |archive-date=2015-09-10 |url-status=live|title=Protecting the LHC from itself|last=Yurkewicz|first=Katie|website=Symmetry Magazine}}</ref>

Glassworking tools are often made from graphite since it will not stick to hot molten glass, unlike metal tools and moulds which require coatings or lubricants, which are themselves often graphite-based. [[Glass production|Automated glassworking]] machines make significant use of graphite for handling the molten glass and freshly formed items.<ref>{{Cite web|last1=Olmec Advanced Materials |title=How graphite is used in the glass and fibreglass industries |url=https://www.olmec.co.uk/graphite_and_carbon_use_in_glass_ceramics_industry.htm |date=2019 |access-date=19 January 2019}}</ref><ref>{{Cite web |date=2016-10-18 |title=Breaking the Mold |url=https://www.lubesngreases.com/magazine/22_11/breaking-the-mold/ |access-date=2025-01-25 |website=Lubes'N'Greases |language=en-US}}</ref>

==Research and innovation==
[[File:Distribution of graphite-related patent families by source type.png|thumb|Distribution of graphite-related patent families by source type - 2012–2022]]
[[File:Innovation maturity matrix Graphite.jpg|thumb|Innovation maturity matrix of graphite]]
Globally, over 60,000 [[patent]] families in graphite technologies were filed from 2012 to 2021. [[Patent application|Patents were filed]] by applicants from over 60 countries and regions. However, graphite-related patent families originated predominantly from just a few countries. [[China]] was the top contributor with more than 47,000 patent families, accounting for four in every five graphite patent families filed worldwide in the last decade. Among other leading countries were [[Japan]], the [[South Korea|Republic of Korea]], the [[United States]] and the [[Russia|Russian Federation]]. Together, these top five countries of applicant origin accounted for 95 percent of global patenting output related to graphite.<ref name="World Intellectual Property Organization.-2023">{{Cite journal |date=2023 |title=Patent Landscape Report - Graphite and its applications |url=https://www.wipo.int/publications/en/details.jsp?id=4649&plang=EN |access-date=2023-11-13 |website=www.wipo.int |publisher=[[WIPO]] |doi=10.34667/tind.47589 |language=en |author1=World Intellectual Property Organization. |series=Patent Landscape Reports }}</ref>

Among the different graphite sources, [[flake graphite]] has the highest number of patent families, with more than 5,600 filed worldwide from 2012 to 2021. Supported by active [[research]] from its commercial entities and research institutions, China is the country most actively exploiting flake graphite and has contributed to 85 percent of global patent filings in this area.

At the same time, innovations exploring new synthesis methods and uses for artificial graphite are gaining interest worldwide, as countries seek to exploit the superior material qualities associated with this man-made substance and reduce reliance on the natural material. Patenting activity is strongly led by commercial entities, particularly world-renowned battery manufacturers and [[anode]] material suppliers, with patenting interest focused on [[Electric battery|battery]] anode applications.<ref name="World Intellectual Property Organization.-2023" />

The exfoliation process for bulk graphite, which involves separating the [[carbon]] layers within graphite, has been extensively studied between 2012 and 2021. Specifically, ultrasonic and thermal exfoliation have been the two most popular approaches worldwide, with 4,267 and 2,579 patent families, respectively, significantly more than for either the chemical or electrochemical alternatives.

Global patenting activity relating to ultrasonic exfoliation has decreased over the years, indicating that this low-cost technique has become well established. Thermal exfoliation is a more recent process. Compared to ultrasonic exfoliation, this fast and solvent-free thermal approach has attracted greater commercial interest.<ref name="World Intellectual Property Organization.-2023" />

As the most widespread anode material for [[Lithium-ion battery|lithium-ion batteries]], graphite has drawn significant attention worldwide for use in [[Electric battery|battery]] applications. With over 8,000 patent families filed from 2012 to 2021, battery applications were a key driver of global graphite-related inventions. Innovations in this area are led by battery manufacturers or anode suppliers who have amassed sizable patent portfolios focused strongly on battery performance improvements based on graphite [[anode]] innovation. Besides industry players, academia and research institutions have been an essential source of innovation in graphite anode technologies.

Graphite for [[polymer]] applications was an innovation hot topic from 2012 to 2021, with over 8,000 patent families recorded worldwide. However, in recent years, in the top countries of applicant origin in this area, including China, Japan and the United States of America (US), patent filings have decreased.<ref name="World Intellectual Property Organization.-2023" />

Graphite for [[Ceramic engineering|manufacturing ceramics]] represents another area of intensive research, with over 6,000 patent families registered in the last decade alone. Specifically, graphite for [[refractory]] accounted for over one-third of ceramics-related graphite patent families in China and about one-fifth in the rest of the world. Other important graphite applications include high-value ceramic materials such as [[carbide]]s for specific industries, ranging from electrical and electronics, aerospace and precision engineering to military and [[Nuclear graphite|nuclear applications]].

[[Brush (electric)|Carbon brushes]] represent a long-explored graphite application area. There have been few inventions in this area over the last decade, with less than 300 patent families filed from 2012 to 2021, very significantly less than between 1992 and 2011.

[[Biomedicine|Biomedical]], [[sensor]], and [[conductive ink]] are emerging application areas for graphite that have attracted interest from both academia and commercial entities, including renowned universities and multinational corporations. Typically for an [[Emerging technologies|emerging technology]] area, related [[Patent application|patent families were filed]] by various organizations without any players dominating. As a result, the top applicants have a small number of [[inventions]], unlike in well-explored areas, where they will have strong technology accumulation and large patent portfolios. The innovation focus of these three emerging areas is highly scattered and can be diverse, even for a single applicant. However, recent inventions are seen to leverage the development of graphite [[nanomaterials]], particularly graphite [[nanocomposite]]s and [[graphene]].<ref name="World Intellectual Property Organization.-2023" />

==See also==
{{div col|colwidth=18em}}
*[[Balama mine]]
*[[Carbon (fiber)|Carbon fiber]]
*[[Carbon nanotube]]
*[[Exfoliated graphite nano-platelets]]
*[[Fullerene]]
*[[Graphene]]
*[[Graphitizing and non-graphitizing carbons]]
*[[Intumescent]]
*[[Lonsdaleite]]
*[[Passive fire protection]]
*[[Pyrolytic carbon]]
{{div col end}}

==Sources==
{{Free-content attribution
| title = Patent Landscape Report - Graphite and its applications
| publisher = WIPO
| documentURL = https://www.wipo.int/edocs/pubdocs/en/wipo-pub-1083-en-patent-landscape-report-graphite-and-its-applications.pdf
| license = CC-BY
}}

==References==
{{reflist}}

==Further reading==
* {{Cite journal |last1=Lipson |first1=H. |last2=Stokes |first2=A. R. |doi=10.1038/149328a0 |title=A New Structure of Carbon |journal=Nature |volume=149 |issue=3777 |page=328 |year=1942 |bibcode=1942Natur.149Q.328L |s2cid=36502694 |doi-access=free}}
* {{cite report|author1=C.Michael Hogan |author2=Marc Papineau |title=[[Phase I Environmental Site Assessment]], Asbury Graphite Mill, 2426–2500 Kirkham Street, Oakland, California, Earth Metrics report 10292.001|date= December 18, 1989|display-authors=etal}}
* {{cite book| author1=Klein, Cornelis| author2=Cornelius S. Hurlbut, Jr.| year=1985| title=Manual of Mineralogy: after Dana| publisher=Wiley| edition=20th| isbn=978-0-471-80580-9| url-access=registration| url=https://archive.org/details/manualofmineralo00klei}}
* {{cite book|author=Taylor, Harold A.|title=Graphite|series=Financial Times Executive Commodity Reports |location=London| publisher=Mining Journal Books |year=2000| isbn=978-1-84083-332-4}}
* {{cite book|author=Taylor, Harold A.|title=Graphite|series=Industrial Minerals and Rocks|edition=7th |location=Littleton, CO|publisher=AIME-Society of Mining Engineers| year=2005 |isbn=978-0-87335-233-8}}

==External links==
{{Commons category|Graphite}}
*[https://web.archive.org/web/20131004215345/http://www.northerngraphite.com/wp-content/uploads/2010/08/Concern-over-battery-grade-graphite-supplies.pdf Battery Grade Graphite]
*[http://www.minerals.net/mineral/graphite.aspx Graphite at Minerals.net]
*[https://web.archive.org/web/20050522074754/http://mineral.galleries.com/minerals/elements/graphite/graphite.htm Mineral galleries]
*[http://www.mineral-exploration.de/maps/worldgraphitemapen.gif Mineral & Exploration] – Map of World Graphite Mines and Producers 2012
*[http://www.mindat.org/show.php?id=1740&ld=1&pho= Mindat w/ locations]
*[http://www.chemguide.co.uk/atoms/structures/giantcov.html giant covalent structures]
*[http://www.phy.mtu.edu/~jaszczak/graphite.html The Graphite Page]
*[http://www.vega.org.uk/video/programme/316 Video lecture on the properties of graphite by M. Heggie], [[University of Sussex]]
*[https://www.cdc.gov/niosh/npg/npgd0306.html CDC – NIOSH Pocket Guide to Chemical Hazards]
* [[usgs.gov]] (Mineral Commodity Summaries 2025): [https://pubs.usgs.gov/periodicals/mcs2025/mcs2025.pdf#page=88 Graphite (natural)] 

{{Allotropes of carbon}}
{{Coal}}

{{Authority control}}

[[Category:Graphite| ]]
[[Category:Native element minerals]]
[[Category:Non-petroleum based lubricants]]
[[Category:Dry lubricants]]
[[Category:Visual arts materials]]
[[Category:Refractory materials]]
[[Category:Electrical conductors]]
[[Category:Hexagonal minerals]]
[[Category:Minerals in space group 186]]
[[Category:Minerals in space group 194]]
[[Category:Industrial minerals]]
[[Category:Semimetals]]