Is a Potassium Aluminum Silicate with formula KaLSi3O8 and hardness of 6.
Orthoclase is a polymorph of other minerals that share the same chemistry, but have different crystal structures. If positive identification between these minerals can not be made by field methods, then the specimen may simply be referred to as a potassium feldspar or K-spar.
It occur in various colors ,such as pale yellow, greenish,grey and colorless.
This gem is eye clean and comes from Madagascar.Cut by the master cutter Luigi Mariani.