Zultanite, a gem variety of diaspore, only occurs in the mountainous region of Anatolia, Turkey. The gem exhibits the optical property called "color change." Zultanite gems turn from yellowish-green to purplish-pink depending on the light source. Sizes over 5 carats are very rare. Gem quality crystals were first discovered in the early 1980s, but only recently have they been commercially mined. Zultanite is a natural gem that has not been enhanced or treated. This Zultanite gem is a nice upgrade to the two diaspores already in the Collection.