Rock & Mineral Encyclopedia

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

Majorite

An ultra-high-pressure garnet with silicon in the octahedral site, formed in the deep mantle transition zone and in shocked meteorites.

A fine-grained, strongly foliated rock formed deep in fault zones where rocks flowed and ground down rather than fracturing.

A blue-hued, high-pressure metamorphic schist colored by the amphibole glaucophane, formed in cold, deep subduction zones.