Rock & Mineral Encyclopedia

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

Regency Rose Agate

A prized plume agate with rose-pink and red feathery inclusions suspended in clear chalcedony, from the western U.S.

A celebrated plume agate from the Oregon-Idaho border, known for dramatic black, gold, and red plumes in clear chalcedony.

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

The red, chromium-colored variety of corundum, prized as one of the most valuable colored gemstones and second only to diamond in hardness.

A black metallic manganese iron oxide famous for sharp cubic crystals, classically found with red beryl and topaz in Utah rhyolite.

Translucent smoky-gray obsidian that transmits a hazy light, intermediate between clear and fully black volcanic glass.

An iron-rich orthopyroxene prized for its warm bronze schiller, a metallic-looking sheen created by tiny mineral inclusions.