Rock & Mineral Encyclopedia

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

Unakite

An altered granite mottled pink and green from feldspar and epidote, popular as a tough, colorful ornamental rock.

An agate whose layered, segmented banding resembles the jointed stalks and leaves of bamboo.

A brown fossiliferous chalcedony packed with spiral freshwater snail shells, technically agatized fossil rock from Wyoming.

A soft, lightweight siliceous sedimentary rock made of fossil diatom remains, prized as a fine natural abrasive and polishing powder.

A fractured and re-cemented agate whose angular broken bands resemble crumbling walls and ruined cityscapes when polished.