Why not ? Black diamond ring has a history:
Dead cat turned into black diamond ring :
London: A British woman, who was left distressed over the death of her pet cat, has turned him into a one-third-of-a-carat black diamond with the help of a US firm.
Sue Rogers then had the rock set in a gold ring so that her beloved pet could stay with her all the time.
Black cat Sooty is believed to be the only black diamond in the world created from a pile of ashes.