Characteristics of Gypsum:

Chemical Name: Calcium sulphate dihydrate

Formula: CaSO4 2H2O

Colors: Colorless, white

Structure: Monoclinic

Hardness: 2

Specific Gravity: 2.3

Refractive Index: 1.52-1.53

Lustre: Subvitreous to pearly

Streak: White

Locations: Mexico, USA

What is Gypsum? 

Transparent crystals of Gypsum are called selenite, and name after the Greek moon goddess, Selene. The name may originate from the ancient belief that certain transparent crystals waxed and waned with the moon, and the crystal is still popular with enthusiast of spiritual gems. A fibrous variety of selenite with a silky lustre is known as “satin spar”; when cut en cabochon, fibrous Gypsum produces a cat’s eye effect, but it is too soft for general wear.