Rock & Mineral Encyclopedia

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

Outlaw Jasper

A boldly patterned western jasper in browns, reds, and golds, prized by lapidaries for its dramatic scenic and brecciated figures.

A chemical deposit precipitated around hot springs and geysers, either siliceous (geyserite) or calcareous, forming delicate terraces and crusts.

A high-temperature potassium feldspar that forms glassy crystals in fast-cooled volcanic rocks, sometimes cut as a moonstone gem.

A banded, metamorphosed iron formation in which bright red jasper alternates with silvery hematite or magnetite layers.

A pale, silvery schist dominated by paragonite, the sodium-rich white mica, formed in aluminous metamorphic rocks.

A green ornamental stone, often serpentine-rich marble or verde antique, valued for its rich green color and white veining.

Ancient chemically deposited rock of alternating iron-oxide and silica bands recording Earth's early oxygenation and a major iron ore source.

A brecciated, chatoyant quartz with swirling blue, gold, and brown fibers that shimmer like a stormy sky.

A rock formed from hot pyroclastic flows, often welded, sometimes containing flattened glass lenses called fiamme.

A rare, ancient ultramafic volcanic rock formed from extremely hot magma, famous for its spinifex texture.