Rock & Mineral Encyclopedia

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

Ruby in Zoisite

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

A deep wine-red to maroon tourmaline colored by manganese, a rich darker-toned member of the red-pink rubellite family.

A prized plume agate from near Carey, Idaho, showing red, pink and black feathery plumes floating in translucent chalcedony.

The potassium-rich feldspar group - orthoclase, microcline, and sanidine - a major rock-forming mineral often recognized by its salmon-pink color.

A vivid green chromium-bearing diopside, an affordable emerald-like gem mined largely in Siberia.

A schist derived from clay-rich sediments, rich in mica and often bearing index minerals like garnet, staurolite, or kyanite.

A hydrated volcanic glass with pearly, onion-like concentric cracks that pops into lightweight white granules when heated.

A pale jasper threaded with black, fern-like mineral dendrites that mimic plants, trees, and frost despite being inorganic.