Rock & Mineral Encyclopedia

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

Chrysocolla

A vivid blue-green hydrated copper silicate, soft on its own but prized as a gem when hardened by intergrown quartz or chalcedony.

A striking rock of green zoisite studded with red-pink ruby crystals and black hornblende, also called anyolite.

Tourmaline crystals displaying two or more distinct colors at once, including the famous pink-and-green watermelon variety.

A soft pink common opal from the Peruvian Andes, prized for its opaque rosy color rather than play-of-color.

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

A banded, metamorphosed iron formation in which bright red jasper alternates with silvery hematite or magnetite layers.