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

Natural emerald crystals still embedded in their host rock, prized as mineral specimens that show how the gem grew in place.

The natural crystal form of morganite, the manganese-colored pink-to-peach variety of beryl popular in romantic jewelry.

Aquamarine crystals still attached to their natural host rock, prized as mineral specimens showing beryl in its original pocket setting.

The natural crystalline form of emerald, the prized green chromium-and-vanadium variety of beryl and the May birthstone.

The blue iron-bearing variety of beryl, forming clear hexagonal crystals prized both as specimens and as a March birthstone gem.

A rare mushroom-shaped tourmaline growth habit, typically magnesium-rich dravite/uvite, prized by collectors for its fungus-like cap-and-stem form.

The smoky brown to gray variety of quartz, colored by natural irradiation, valued as both a gemstone and crystal specimen.

An unusually pure, transparent-to-translucent obsidian with few inclusions; truly water-clear specimens are rare in nature.

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

A naturally magnetic black iron oxide and a major iron ore; strongly magnetic specimens are known as lodestone.

A striking lead chromate mineral prized for its brilliant orange-red prismatic crystals, with the finest specimens from Tasmania.