Rock & Mineral Encyclopedia

Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.

Kalahari Jasper

An African picture jasper from the Kalahari region with warm desert-toned banding evoking dunes and savanna.

A prized Mexican jasper known for pastel green, lavender, and cream orbicular patterns that take an exceptional polish.

A banded jasper with cream, tan, and brown layers resembling snakeskin, often sourced from Madagascar.

A black volcanic glass that reveals concentric rainbow bands of color when cut and polished against the light.

Beryl displaying chatoyancy, a bright moving band of light, caused by parallel tube-like inclusions when cut as a cabochon.

Aquamarine that shows a bright moving band of light, or cat's eye, caused by parallel needle-like inclusions when cut as a cabochon.

Tourmaline displaying chatoyancy, a moving band of light caused by parallel tube-like inclusions, when cut as a cabochon.

A trade name for rainbow-sheen obsidian whose aligned nanoparticles produce shifting aurora-like bands of color.

A banded jasper showing parallel ribbon-like stripes of contrasting color formed by layered silica and mineral deposition.

Black volcanic glass that flashes flame-like bands of iridescent color when light strikes aligned nanoscale inclusions.

The blue-grey relative of tiger's eye, a chatoyant quartz showing a shifting band of light like a bird of prey's eye.

Black volcanic glass laced with delicate web-like veins of contrasting color, formed by flow banding and fine crystallization.

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.