Rock & Mineral Encyclopedia

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

Itabirite

A metamorphosed banded iron formation of alternating quartz and iron-oxide layers, mined as a major iron ore.

A soft, talc-rich metamorphic rock with a soapy feel, easily carved and highly heat-resistant for cookware and sculpture.

A green quartz speckled with shimmering fuchsite mica that produces a glittering aventurescence, popular as an affordable ornamental stone.

A coarse-grained, speckled intrusive rock built from quartz, feldspar, and mica, forming the bedrock of the continents.

A rich green, fuchsite-rich metamorphic rock from southern Africa, prized as a carving and ornamental stone.

A rare high-pressure metamorphic schist defined by the diagnostic assemblage of talc plus kyanite, often pale and silvery.

A dark, mineral-rich dike rock with abundant mica or amphibole phenocrysts set in a fine groundmass, often associated with gold and diamonds.

A dark, dense metamorphic rock dominated by hornblende and plagioclase, formed by medium- to high-grade metamorphism of basalt.

A rare ultrapotassic lamproite rich in phlogopite mica and diopside, classically from the Leucite Hills of Wyoming.

A pegmatitic granite in which quartz and feldspar intergrow to resemble ancient runic or Hebrew script.

A general term for light-colored, fine-grained volcanic rocks rich in quartz and feldspar, like rhyolite.