Obsidian
From The Gemology Project
Obsidian (named after the roman, Obsius) is a volcanic glass.
Contents
Diagnostics
Color
Its color is black, grey, brown, green and can be gold or silver due to inclusions
Diaphaneity
Transparent to opaque
Hardness
Obsidian has a hardness of 5-5 1/2
Specific gravity
Obsidian has a density of 2.35-2.60
Refractive index
Obsidian is singly refractive with an R.I. range of 1.45 to 1.55
Varieties
- Snow flake obsidian is the trade name for an obsidian with grey-white, ball shaped inclusions of Spherulites found in Mexico and the United States
Localities
Deposits are found in the United States, Mexico, Japan, Itally, Iceland, Indonesia and Equador.
