Rock & Mineral Encyclopedia

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

Bamboo Agate

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

A banded chalcedony with straight, ribbon-like parallel layers, often cut across the bands for striking striped cabochons.

A hard, fine-grained sedimentary silica rock that breaks with sharp conchoidal edges, prized by ancient toolmakers.

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

A prized plume agate from near Carey, Idaho, showing red, pink and black feathery plumes floating in translucent chalcedony.

A soft sky-blue chalcedony from the Owyhee region of Oregon and Idaho, prized for its calming, opaque powder-blue color.

A warm cognac-brown to reddish-brown tourmaline, typically magnesium-rich dravite, prized for its rich whisky-like color.

A rare brown chalcedony containing thin iron-oxide layers that produce flashing, fiery rainbow iridescence like trapped flames.