Mineral Group · 6 minerals
Organic & Biogenic Gems
Minerals
6
Hardness
2.5-7 Mohs
Crystal Systems
Amorphous, Orthorhombic, Trigonal
What Defines the Organic Group
Not minerals in the strict sense, but natural gem materials produced by biological processes or preserved organic material. Amber is fossilized tree resin. Pearl is layers of aragonite deposited by mollusks. Coral is calcium carbonate from marine organisms. Jet is fossilized wood. Ammolite is iridescent fossilized shell.
Minerals in This Group
Amber
The Window to Prehistoric Life
Hardness 2.5·Organic Gem (Fossilized Resin)
Ammolite
The Seven Color Gem
Hardness 4·Organic Gemstone (Fossilized Aragonite)
Coral
The Garden of the Sea
Hardness 3.5·Organic Gem (Calcium Carbonate)
Jet
The Mourning Stone
Hardness 3·Organic Gem (Fossilized Wood)
Pearl
The Gem of the Sea
Hardness 3·Organic Gem (Biomineral)
Petrified Wood
Time Written in Stone
Hardness 7·Fossilized Organic Material