Rock & Mineral Encyclopedia

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

Rutilated Quartz

Clear or smoky quartz threaded with golden to reddish needles of rutile, also poetically called Venus hair stone.

Tabular quartz crossed by a milky white thread-like line marking where the crystal repeatedly cracked and re-healed.

A dull, resinous volcanic glass similar to obsidian but with higher water content and a waxy pitch-like luster.

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

A red-toned banded chalcedony colored by iron oxides, ranging from natural carnelian-like reds to heat-treated stones.

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.

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

A glassy calcium borosilicate forming wedge-tipped prismatic crystals, usually colorless to pale yellow or pink, sometimes faceted as a gem.

A vivid Australian jasper-like silica stone in earthy reds, yellows, and purples, formed from silicified radiolarian sediment.

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

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

A trademarked deep purple-red rhodolite garnet from India, named for its rich grape-like color from the pyrope-almandine series.