Group IV elements have some interesting stories attached to
them. Carbon is found in Sri Lanka in the form of graphite. This is used
as a high temperature lubricant, an inert electrode and for absorbing neutrons
in nuclear reactors. Carbon is also found in South Africa as
diamond. Uses include cutting drilling and in jewellery. Conflict
diamonds have been used to fund wars in Angola and Sierra Leone. http://www.un.org/peace/africa/Diamond.html
Gem sized diamonds have been available commercially since about 2003.
The best cannot be distinguished from natural diamonds other than by using
techniques such as X-ray crystallography. Any carbon can be used even
yours!
"LifeGem holds a patent on a process for extracting carbon from cremated
remains. Human or pet, they take a few ounces of ashes, process it into
graphite, and then using a high-pressure system, turn the graphite into diamonds
– one or many, however the customer prefers." source http://www.damninteresting.com/?p=328