Rock & Mineral Encyclopedia

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

Pyrite

The brassy iron sulfide mineral famous as 'fool's gold,' known for sharp metallic cubes and a much higher hardness than real gold.

A brassy copper-iron sulfide that is the world's most important copper ore, often showing colorful iridescent tarnish.

The yellow variety of beryl, also called heliodor or golden beryl, colored by iron and valued for its bright color and durability.

A warm earth-toned jasper from Madagascar in flowing reds, oranges and golds, also called desert jasper, discovered in the early 2000s.

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

A banded combination rock of golden tiger's eye, red jasper, and metallic hematite, formed in ancient iron deposits.

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

An intensely blue metamorphic rock of lazurite flecked with golden pyrite, prized for millennia as a gemstone and ultramarine pigment.

An opaque grey-brown common opal forming nodules and concretions, historically called liver opal for its dull brownish color.