Spinel is a durable gemstone that was long mistaken for ruby in its red variety. Kuh-I-Lal (Tajikistan) has produced spinel (long mistaken for ruby) for over a millennium. The Black Prince Ruby, currently part of the British Crown jewels, appeared during the 14th century and is believed to come from this mine (Hughes, 2013).  Other old mining areas include Sri Lanka and Burma. More recent deposits are found in Madagascar, East Africa and Vietnam. Spinel comes in a wide variety of different colors. Spinel is not frequently treated.