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.

A purple-hued common opal, much of it the Mexican "morado" type, valued for even violet color rather than play-of-color.

The purple variety of quartz, colored by iron and natural irradiation, prized as the classic violet birthstone of February.

Natural emerald crystals still embedded in their host rock, prized as mineral specimens that show how the gem grew in place.

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

A man-made glittering glass packed with tiny copper crystals, traditionally reddish-brown but also made in blue and green.

A natural bicolor quartz blending amethyst purple with prasiolite green in a single crystal, prized as a metaphysical heart-crown stone.

The hardest known natural material, a crystalline form of pure carbon prized as the ultimate gemstone for its brilliance and fire.

The pure colorless variety of beryl, valued as crystal specimens and as a brilliant alternative to clearer gemstones.

Transparent, colorless beryl (goshenite), the pure form of the species valued for its clarity, hardness, and well-formed crystals.