Rock & Mineral Encyclopedia

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

Fluorite

A soft, colorful calcium fluoride mineral famous for cubic crystals, perfect octahedral cleavage, and fluorescence under UV light.

Quartz colored or coated by golden iron oxides such as limonite or goethite, giving a warm sunlit yellow glow.

A natural bicolor quartz that combines purple amethyst and golden citrine in a single crystal.

A lead molybdate mineral famous for thin, brilliant orange to yellow tabular crystals, prized by collectors and an ore of molybdenum.

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

A lead phosphate secondary mineral known for barrel-shaped green to yellow crystals formed in oxidized lead deposits.

A nickel sulfide famous for delicate brass-yellow hairlike crystals that form radiating sprays inside cavities and geodes.