Rock & Mineral Encyclopedia

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

Pelitic Schist

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

A vivid yellow-and-black banded stone from Indonesian volcanic vents, colored by sulfur, arsenic minerals and iron oxides, not true jasper.

A calc-silicate rock formed by chemical exchange between magma and carbonate rock, often rich in garnet and economically important ore minerals.

A rare black carbon-rich rock from Russia, noted for containing fullerenes and ranging from dull mineralized stone to lustrous noble shungite.

A soft copper sulfide famous for its intense indigo-blue color and dazzling iridescent metallic sheen, prized by collectors.

The rare colorless variety of tourmaline, named from the Greek for 'without color' and prized by collectors.

A rare Australian jasper from the Pilbara with bold red, yellow, and black abstract patterns, prized by collectors.

A dark gray copper sulfide that is one of the richest copper ores, prized by collectors when found as rare sharp crystals.

Fossil bone in which opal has replaced the original tissue, sometimes showing play-of-color, a rare collector fossil.

The rare colorless-to-white grossular garnet, also called leuco garnet, prized by collectors for its purity and unusual lack of color.

The colorless to milky-white variety of beryl, known mineralogically as goshenite and once used to imitate diamond and other gems.

A rare mushroom-shaped tourmaline growth habit, typically magnesium-rich dravite/uvite, prized by collectors for its fungus-like cap-and-stem form.