Rock & Mineral Encyclopedia

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

Fireworks Obsidian

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.

Obsidian with a hazy, cloud-like translucency caused by uneven distribution of tiny bubbles or incipient crystallites in the glass.

A natural volcanic glass with rich brown and black mahogany-like swirls created by iron oxide inclusions.

A sought-after elbaite tourmaline in teal hues that blend blue and green, prized for its ocean-like color.

A hydrated volcanic glass with pearly, onion-like concentric cracks that pops into lightweight white granules when heated.

Black volcanic glass that flashes flame-like bands of iridescent color when light strikes aligned nanoscale inclusions.

Black volcanic glass laced with delicate web-like veins of contrasting color, formed by flow banding and fine crystallization.

A black volcanic glass threaded with delicate grey, swirling lace-like bands of flow lines that show beautifully when polished.

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

A precious opal showing dominant peacock-like blue, green and teal play-of-color, often on Ethiopian material.

Fine, golden, hair-like strands of basaltic volcanic glass spun from fluid lava droplets during eruptions, named for the Hawaiian volcano goddess.

The blue-grey relative of tiger's eye, a chatoyant quartz showing a shifting band of light like a bird of prey's eye.

Jelly Garnet is a translucent grossular garnet whose soft, glassy, gummy-looking body gives it a jelly-like appearance.

A rare sky-blue variety of pectolite found only in the Dominican Republic, prized for its sea-like color and white volcanic patterning.