Crystal Yellow Sapphire

Chemical Formula

Al₂O₃

Color

White, Colorless, Blue, Green, Yellow, Orange, Brown, Pink, Purple, Gray, Black, Multicolored

Hardness

9

Crystal System

Hexagonal

Refractive Index

1.76 - 1.77

SG

3.9 - 4.1

Transparency

Transparent to opaque

Double Refraction

.0008

Luster

Vitreous to adamantine

Cleavage

None, but may exhibit parting

Mineral Class

Corundum