Your friend sort of gave you some poor information.
Check out the following links for information on/about Blood Diamonds AKA conflict diamonds:
A
blood diamond (also called a
conflict diamond or a
war diamond) is a
diamond mined in a
war zone and sold, usually clandestinely, in order to finance an insurgent or invading army's war efforts.
[1] [2]
http://en.wikipedia.org/wiki/Conflict_diamond
http://www.un.org/peace/africa/Diamond.html
http://abc.net.au/news/newsitems/200610/s1776141.htm
http://news.nationalgeographic.com/n...-diamonds.html
http://www.stopblooddiamonds.org/
And diamonds are no where near as rare as the owners of the mines and the rest of the industry
would like us to believe. Supply is kept short by storing supplies in vaults.
You can check that out on your own.