Rock & Mineral Encyclopedia

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

Howlite

A white, porous borate mineral webbed with gray-black veins, widely dyed to imitate turquoise and other stones.

A prized blue to blue-green copper-aluminium phosphate, often veined with dark matrix, treasured for jewelry across many cultures.

A magnesium carbonate mineral, usually chalky white with grey veining, widely dyed to imitate turquoise and other stones.

A vivid turquoise-blue glass sold as obsidian; this bright color is virtually always manufactured rather than natural volcanic glass.

A soft, soothing powder-blue variety of calcite, a common calcium carbonate mineral often sold as gentle tumbled stones.

A colorful trade-name material, often dyed and reconstituted, sold as jasper; vivid blues and greens are typically artificially enhanced.

A copper-iron sulfide ore famous for its iridescent peacock-like purple and blue tarnish; often sold as treated chalcopyrite.

A man-made opalescent glass that glows milky blue in reflected light and warm orange when backlit, often sold as a crystal.

A solid jet-black chalcedony, usually a dyed and treated agate, prized for sleek polished beads, cabochons, and intaglios.

A group of green magnesium silicate minerals with a smooth, waxy feel, often carved and sometimes sold as imitation jade.