Glauberite
2.34 ct
Octagon Cut
13.80 x 6.40 x 4.20 mm
California
USA
max7472x

Glauberite

is a sodium calcium sulfate with formula Na2Ca(SO4)2 and hardness of 2.5 .

Named in 1808 by Brongniart for its chemical similarity to Glauber's salt, Na2SO4·10H2O, discovered by German alchemist Johann Rudolf Glauber (1604-1668). Natural Glauber's salt is the distinct species mirabilite. ( from Wikipedia)

Is a very sensitive mineral to water with properties similar to the normal salt,therefore must be stored in a dry place, better not exposed to air,or it may deteriorate .

Therefore the cutting and polish is difficult and very few stones are available in the market.

It comes from California.