Rock & Mineral Encyclopedia

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

Flame Jasper

A fiery jasper whose red, orange, and yellow plumes lick across the stone like flames against an earthy background.

A rare translucent yellow-green volcanic glass from the Macusani region of Peru, valued by faceters and sometimes confused with tektites.

Rounded nodules of translucent obsidian, named after a Native American legend, that glow smoky brown when held to light.

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

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

A glittery, strongly foliated rock made mostly of aligned mica flakes that split into thin, shiny sheets.

An opaque, iron-rich basaltic volcanic glass formed by the rapid chilling of basalt lava, darker and denser than rhyolitic obsidian.

A bright yellow native element mineral that forms around volcanic vents and hot springs and burns with a blue flame.

A soft lithium-bearing mica with a lilac to purple color and pearly, flaky sheen, an important ore of lithium.

A rare brown chalcedony containing thin iron-oxide layers that produce flashing, fiery rainbow iridescence like trapped flames.