Rock & Mineral Encyclopedia

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

Citrine

The golden-yellow variety of quartz, ranging from pale lemon to deep madeira amber, often produced by heating amethyst.

A vivid greenish-yellow quartz, usually heat-treated or irradiated, prized for its clean clarity and bright lemon color.

The soft pink, usually cloudy variety of quartz colored by trace titanium or microscopic inclusions, popular for carvings and beads.

A natural bicolor quartz that combines purple amethyst and golden citrine in a single crystal.

A pale green variety of quartz, usually created by heat-treating amethyst, often marketed as green amethyst.

An altered granite of pink feldspar, green epidote and quartz, mottled pink-and-green and popular as a tumbled and carving stone.

A deep black variety of banded chalcedony, often closely related to or treated like onyx, used for jewelry and carvings.

An opaque, often colorfully patterned variety of chalcedony quartz, popular for tumbling, carving, and jewelry.

An opaque green variety of chalcedony quartz colored by iron and chlorite-group inclusions, prized as a durable carving and cabochon stone.