Editing Carbon (section)

==Applications==
{{More citations needed section|date=April 2025}}
{{Gallery
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|File:Mechanical pencil lead spilling out 051907.jpg
 |Pencil leads for mechanical pencils are made of [[graphite]]
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|File:Charcoal sticks 051907.jpg
 |Sticks of vine and compressed [[charcoal]]
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|File:Kohlenstofffasermatte.jpg 
 |A cloth of woven carbon fibres
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|File:SiC p1390066.jpg
 |[[Silicon carbide]] [[single crystal]]
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|File:C60-Fulleren-kristallin.JPG
 |The ''C''{{sub|60}} fullerene in crystalline form
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|File:Tungsten carbide.jpg
 |[[Tungsten carbide]] [[endmills]]
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Carbon is essential to all known living systems, and without it life as we know it could not exist (see [[alternative biochemistry]]). The major economic use of carbon other than food and wood is in the form of hydrocarbons, most notably the fossil fuel methane gas and crude oil (petroleum). Crude oil is distilled in refineries by the [[petrochemical industry]] to produce gasoline, kerosene, and other products. [[Cellulose]] is a natural, carbon-containing polymer produced by plants in the form of wood, cotton, linen, and [[hemp]]. Cellulose is used primarily for maintaining structure in plants. Commercially valuable carbon polymers of animal origin include wool, cashmere, and silk. Plastics are made from synthetic carbon polymers, often with oxygen and nitrogen atoms included at regular intervals in the main polymer chain. The raw materials for many of these synthetic substances come from crude oil.

The uses of carbon and its compounds are extremely varied. It can form [[alloy]]s with iron, of which the most common is [[carbon steel]]. Graphite is combined with clays to form the 'lead' used in pencils used for writing and drawing. It is also used as a lubricant and a pigment, as a moulding material in glass manufacture, in [[electrode]]s for dry batteries and in [[electroplating]] and [[electroforming]], in [[brush (electric)|brushes]] for [[electric motors]], and as a [[neutron moderator]] in [[nuclear reactor]]s.

Charcoal is used as a drawing material in artwork, barbecue grilling, [[iron smelting]], and in many other applications. Wood, coal and oil are used as fuel for production of energy and heating. Gem quality diamond is used in jewelry, and [[industrial diamond]]s are used in drilling, cutting and polishing tools for machining metals and stone. Plastics are made from fossil hydrocarbons, and [[carbon fiber]], made by [[pyrolysis]] of synthetic polyester fibers is used to reinforce plastics to form advanced, lightweight composite materials.

Carbon fiber is made by pyrolysis of extruded and stretched filaments of [[polyacrylonitrile]] (PAN) and other organic substances. The crystallographic structure and mechanical properties of the fiber depend on the type of starting material, and on the subsequent processing. Carbon fibers made from PAN have structure resembling narrow filaments of graphite, but thermal processing may re-order the structure into a continuous rolled sheet. The result is fibers with higher [[specific strength|specific tensile strength]] than steel.<ref name="Cantwell-1991">{{cite journal |first1=W. J. |last1=Cantwell |first2=J. |last2=Morton |title=The impact resistance of composite materials&nbsp;– a review |journal=Composites |date=1991 |volume=22 |issue=5 |pages=347–62 |doi=10.1016/0010-4361(91)90549-V}}</ref>

[[Carbon black]] is used as the black pigment in printing ink, artist's oil paint, and water colours, [[carbon paper]], automotive finishes, [[India ink]] and [[laser printer]] toner. Carbon black is also used as a filler in rubber products such as tyres and in plastic compounds. [[Activated charcoal]] is used as an [[absorption (chemistry)|absorbent]] and [[adsorbent]] in [[filter (chemistry)|filter]] material in applications as diverse as gas masks, water purification, and kitchen [[extractor hood]]s, and in medicine to absorb toxins, poisons, or gases from the digestive system. Carbon is used in [[chemical reduction]] at high temperatures. [[Coke (fuel)|Coke]] is used to reduce iron ore into iron (smelting). [[Case hardening]] of steel is achieved by heating finished steel components in carbon powder. [[Carbide]]s of [[silicon carbide|silicon]], [[tungsten carbide|tungsten]], [[boron carbide|boron]], and [[titanium carbide|titanium]] are among the hardest known materials, and are used as abrasives in cutting and grinding tools. Carbon compounds make up most of the materials used in clothing, such as natural and synthetic textiles and leather, and almost all of the interior surfaces in the built environment other than glass, stone, drywall, and metal.
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===Diamonds===
The [[diamond]] industry falls into two categories: one dealing with gem-grade diamonds and the other, with industrial-grade diamonds. While a large trade in both types of diamonds exists, the two markets function dramatically differently.

Unlike [[precious metal]]s such as gold or platinum, gem diamonds do not trade as a commodity. There is a substantial mark-up in the sale of diamonds, and there is not a very active market for resale of diamonds.

Industrial diamonds are valued mostly for their hardness and heat conductivity, with the gemological qualities of clarity and color being mostly irrelevant. About 80% of mined diamonds (equal to about 100 million carats or 20&nbsp;tonnes annually) are unsuitable for use as gemstones and relegated for industrial use (known as ''[[bort]])''.<ref>{{cite book |title=Turning And Mechanical Manipulation |first=Ch. |last=Holtzapffel |publisher=Charles Holtzapffel |date=1856 |url=https://archive.org/details/turningandmecha01holtgoog}} [https://archive.org/details/turningmechanica02holtuoft Internet Archive] {{webarchive|url=https://web.archive.org/web/20160326085110/https://archive.org/details/turningmechanica02holtuoft|date=2016-03-26}}</ref> [[Synthetic diamond]]s, invented in the 1950s, found almost immediate industrial applications; 3&nbsp;billion carats (600&nbsp;[[tonne]]s) of synthetic diamond is produced annually.<ref name="USGS-2009">{{cite web |url=http://minerals.usgs.gov/minerals/pubs/commodity/diamond/ |access-date=2009-05-05 |title=Industrial Diamonds Statistics and Information |publisher=United States Geological Survey |url-status=live |archive-url=https://web.archive.org/web/20090506221551/http://minerals.usgs.gov/minerals/pubs/commodity/diamond/ |archive-date=2009-05-06}}</ref>

The dominant industrial use of diamond is in cutting, drilling, grinding, and polishing. Most of these applications do not require large diamonds; in fact, most diamonds of gem-quality except for their small size can be used industrially. Diamonds are embedded in drill tips or saw blades, or ground into a powder for use in grinding and polishing applications.<ref>{{cite journal |first1=R. T. |last1=Coelho |title=The application of polycrystalline diamond (PCD) tool materials when drilling and reaming aluminum-based alloys including MMC |doi=10.1016/0890-6955(95)93044-7 |journal=International Journal of Machine Tools and Manufacture |volume=35 |date=1995 |pages=761–774 |issue=5 |last2=Yamada |first2=S. |last3=Aspinwall |first3=D. K. |last4=Wise |first4=M. L. H.}}</ref> Specialized applications include use in laboratories as containment for [[high-pressure experiments]] (see [[diamond anvil cell]]), high-performance [[bearing (mechanical)|bearings]], and limited use in specialized windows.<ref>{{cite book |pages=303–334 |title=Materials for infrared windows and domes: properties and performance |first=D. C. |last=Harris |publisher=SPIE Press |date=1999 |isbn=978-0-8194-3482-1}}</ref><ref>{{cite book |first=G. S. |last=Nusinovich |title=Introduction to the physics of gyrotrons |publisher=JHU Press |date=2004 |isbn=978-0-8018-7921-0 |page=229}}</ref> With the continuing advances in the production of synthetic diamonds, new applications are becoming feasible. Garnering much excitement is the possible use of diamond as a [[semiconductor]] suitable for [[microchips]], and because of its exceptional heat conductance property, as a [[heat sink]] in electronics.<ref>{{cite journal |title=120 W CW output power from monolithic AlGaAs (800 nm) laser diode array mounted on diamond heatsink |first1=M. |last1=Sakamoto |first2=J. G. |last2=Endriz |first3=D. R. |last3=Scifres |journal=Electronics Letters |date=1992 |volume=28 |issue=2 |pages=197–199 |doi=10.1049/el:19920123 |bibcode=1992ElL....28..197S}}</ref>