Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Hawk's Eye
The blue-grey relative of tiger's eye, a chatoyant quartz showing a shifting band of light like a bird of prey's eye.
gemstone
Flame Obsidian
Black volcanic glass that flashes flame-like bands of iridescent color when light strikes aligned nanoscale inclusions.
igneous
Cat's Eye Morganite
Pink beryl (morganite) that shows chatoyancy, a moving band of light, when cut as a cabochon, thanks to parallel tube inclusions.
gemstone
Cat's Eye Opal
An opal cut to show chatoyancy, a sharp moving band of light like a cat's eye, usually in honey, green or yellow common opal.
gemstone
Pink Obsidian
A pink to rose volcanic glass; some is natural iron-tinted obsidian while much sold commercially is color-treated glass.
igneous
Blue Obsidian
Blue-colored volcanic glass; genuine natural blue obsidian is very rare, while much blue obsidian on the market is manufactured glass.
crystal
Emerald Green Obsidian
A bright emerald-green glass sold as obsidian; saturated transparent green is manufactured, while rare natural green obsidian is only faintly tinted.
igneous
Pink Lady Obsidian
Obsidian showing a pink-to-rose sheen or hue; natural examples get color from interference effects, while uniform pink material is often manufactured glass.
igneous