Rock & Mineral Encyclopedia

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

Pietersite

A brecciated, chatoyant quartz with swirling blue, gold, and brown fibers that shimmer like a stormy sky.

A chalcedony agate with red, orange, and yellow plume or banding patterns that rise like dancing flames within the stone.

Ancient chemically deposited rock of alternating iron-oxide and silica bands recording Earth's early oxygenation and a major iron ore source.

An altered granite mottled pink and green from feldspar and epidote, popular as a tough, colorful ornamental rock.

A water-bearing massive grossular garnet, usually green or pink, widely used as a tough jade-like carving stone.

A tourmaline displaying two or more distinct colors in a single crystal, prized for natural color zoning like watermelon and bicolor stones.