Rock & Mineral Encyclopedia

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

Clear Quartz

The pure, colorless form of crystalline quartz, valued for its clarity, abundance, and piezoelectric properties used in electronics.

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

Clusters of tiny botryoidal chalcedony spheres resembling bunches of grapes, famously purple, found in Indonesia.

A dark, foliated schist rich in graphite that leaves a grey-black mark and forms from metamorphosed carbon-rich sediments.

A plume agate whose inclusions form upright, bristly clusters resembling the strokes of a paintbrush.

A pale chalcedony agate with cloudy, frost-like white patterning suggesting frost on a window or icy crystalline textures.

Obsidian that has partly crystallized over time, growing pale spherulite clusters within the black glass, as in snowflake obsidian.