Mineral

Sugilite occurs in Japan in the shape of brownish-yellow small grains. Sugilite is named according to the Japanese  petrologist Ken-Ichi-Sugi who found the first sugilite in Japan in 1944.
In India there were found small pink sugilite crystals.
The violet variety of sugilite from Southafrica, which we normally can buy, is a rough composite, mostly mixed with other minerals. Especially chalcedony can be a part of the stone. If there is a lot of chalcedony sugilite can appear to be transparent. The violet color comes from additions of manganese (Mn). Very popular is also blue sugilite which is colored by inclusions of richterite.

Mineral: Sugilite
Family: Sogdianitfamily
Hardness: 6,0-6,5
Specific grav. 2,74
Transparency: opaque
Chem. formula: Natrium-Kalium-Silicat (eisenh.)
(K, Na)(Na, Fe3+)2 (Li2, Fe3+)[Si12, O30]
Crystals: hexagonal
Streak: white