|Gem cut aluminum oxide (corundum).|
These are real rubies and sapphires purchased from http://www.pehnec.com in April 2002. Real because they are chemically and crystallographically indistinguishable from naturally occurring gems (that would cost well into 5 figures). Present in the table because they are man-made (real, but synthetic).
Source: Pehnec Gems
Contributor: Theodore Gray
Acquired: 23 April, 2002