Rock & Mineral Encyclopedia

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

Teepee Canyon Agate

A fortification agate from the Black Hills of South Dakota, known for tight, colorful banding closely related to the famous Fairburn agate.

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

A jasper whose radiating mineral clusters form flower-like rosettes scattered across an earthy background.

A jasper marked with soft feather- or plume-like mineral inclusions that drift through a pale silica body.

A pale jasper threaded with black, fern-like mineral dendrites that mimic plants, trees, and frost despite being inorganic.

The most common sedimentary rock, a fissile mudrock of compacted clay and silt that splits into thin layers.

Agate containing radiating sprays of mineral needles that fan out like bursting stars within the chalcedony.

A cream-colored spotted stone resembling a Dalmatian dog, made of feldspar and quartz dotted with dark mineral grains.

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

A foliated metamorphic rock of calcite mixed with mica, quartz, and calc-silicate minerals, derived from marly sediments.

A high-grade metamorphic rock formed in the deep, hot crust, marked by anhydrous minerals like pyroxene and garnet.

A schist derived from clay-rich sediments, rich in mica and often bearing index minerals like garnet, staurolite, or kyanite.