Rock & Mineral Encyclopedia

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

Azurite

A deep blue copper carbonate mineral that forms in oxidized copper deposits, often alongside green malachite.

A rare deep-blue copper silicate mineral, often fibrous or massive, named for the Shattuck Mine in Arizona and prized by collectors.

A vivid blue-green hydrated copper silicate, soft on its own but prized as a gem when hardened by intergrown quartz or chalcedony.

The pure colorless variety of beryl, valued as crystal specimens and as a brilliant alternative to clearer gemstones.

An opaque blue variety of chalcedony jasper, less common than red or green forms, colored by mineral inclusions.

Blue-colored volcanic glass; genuine natural blue obsidian is very rare, while much blue obsidian on the market is manufactured glass.

The colorless variety of beryl, named after Goshen, Massachusetts, prized for its purity, clarity, and durability.