Editing Carbon (section)

===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>