Rock & Mineral Encyclopedia

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

Ametrine

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

A natural bicolor quartz blending amethyst purple with prasiolite green in a single crystal, prized as a metaphysical heart-crown stone.

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

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