Chemical Composition: Fluorosilicate of aluminium with hydroxyl, Al 2 (F,OH) 2 SiO 4
Refractive Index: 1.61 – 1.64
Specific Gravity: 3.5 – 3.6
Crystal System: Orthorhombic
Moh's Hardness: 8

Topaz occurs in a variety of colours from pink, orange, yellow, brown, blue

colourless. The most common locality for Topaz is Brazil although there are

other sources including Japan, Madagascar, Burma, Pakistan, USA