Rock & Mineral Encyclopedia

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

Rainforest Jasper

An Australian green rhyolite with eye-like orbs and earthy patterns marketed as jasper, evoking dense rainforest foliage.

A dark, foliated schist rich in graphite that leaves a grey-black mark and forms from metamorphosed carbon-rich sediments.

A dark green-and-black stromatolite jasper patterned with swirling orbs, formed from fossilized ancient microbial colonies.

Obsidian colored brown by iron oxide inclusions, frequently banded or swirled with black as in mahogany obsidian.

Black volcanic glass with a warm bronze or coppery sheen produced by light reflecting off aligned microscopic inclusions.

A dark, mineral-rich dike rock with abundant mica or amphibole phenocrysts set in a fine groundmass, often associated with gold and diamonds.