Rock & Mineral Encyclopedia

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

Starburst Agate

Agate containing radiating sprays of mineral needles that fan out like bursting stars within the chalcedony.

A patterned common opal with mottled, leopard-like spots and blotches, prized as an ornamental and cabochon stone.

Tourmaline displaying chatoyancy, a moving band of light caused by parallel tube-like inclusions, when cut as a cabochon.

Black volcanic glass dotted with radiating spherulite bursts that look like exploding fireworks frozen in the stone.

A feldspar gem famous for adularescence, a floating blue-white glow that shimmers across the stone like moonlight.

A banded jasper showing parallel ribbon-like stripes of contrasting color formed by layered silica and mineral deposition.

A rare granitic rock containing concentric, onion-like spheres called orbicules, prized as a striking ornamental stone.

Clear quartz crystals marked by distinctive horizontal ladder-like striations, popularized from Brazil as a metaphysical stone.

A common opal containing dendritic or mossy mineral inclusions that form miniature landscape-like scenes inside the stone.

A pale jasper threaded with black, fern-like mineral dendrites that mimic plants, trees, and frost despite being inorganic.

A water-bearing massive grossular garnet, usually green or pink, widely used as a tough jade-like carving stone.

Quartz colored blue by inclusions of the mineral dumortierite, giving a denim-like blue ornamental stone harder than dumortierite alone.

A precious opal pattern made of tiny, densely packed pinpoint flashes of play-of-color, like sparkling speckles across the stone.

Beryl displaying chatoyancy, a bright moving band of light, caused by parallel tube-like inclusions when cut as a cabochon.