Rock & Mineral Encyclopedia

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

Kalahari Jasper

An African picture jasper from the Kalahari region with warm desert-toned banding evoking dunes and savanna.

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

A yellow to golden banded chalcedony colored by iron, ranging from natural honey tones to dyed commercial stones.

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

A golden-toned opal ranging from translucent common opal to precious stones flashing color against a warm yellow body.

Small, smooth, teardrop-shaped beads of basaltic volcanic glass formed from airborne lava droplets, often paired with Pele's hair.

The highest-rank coal, a hard, lustrous black rock that burns cleanly with little smoke and high heat output.

A Norwegian intrusive rock whose feldspar crystals flash silvery-blue, widely used as blue pearl granite countertops.