Rock & Mineral Encyclopedia

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

Howlite

A white, porous borate mineral webbed with gray-black veins, widely dyed to imitate turquoise and other stones.

A prized blue to blue-green copper-aluminium phosphate, often veined with dark matrix, treasured for jewelry across many cultures.

A nodular rhyolite geode-like ball whose plain exterior hides a star-shaped agate or chalcedony core when cut.

A magnesium carbonate mineral, usually chalky white with grey veining, widely dyed to imitate turquoise and other stones.

Limestone built from tiny rounded ooid grains resembling fish roe, formed in warm, agitated shallow seas.

A limestone made of tiny spherical ooids, resembling fish roe, formed in warm, agitated shallow seas.

A rounded sedimentary nodule cracked internally and filled with veins of yellow calcite, prized for its striking dragon-skin patterning.

A prized Idaho picture jasper from Bruneau Canyon known for brown and cream orbicular egg-rock patterns and scenic landscapes.