Rock & Mineral Encyclopedia

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

Plume Agate

A translucent agate containing delicate three-dimensional feather- or plant-like plumes of mineral inclusions suspended in chalcedony.

An old name for a dull leek-green variety of quartz or chalcedony colored by green mineral inclusions, historically called mother of emerald.

Obsidian formed from two merged lava flows, producing a stone with two distinct bands of sheen or color.

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

A patterned common opal with mottled, leopard-like spots and blotches, prized as an ornamental and cabochon stone.

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

A fiery jasper whose red, orange, and yellow plumes lick across the stone like flames against an earthy background.

A green ornamental stone, often serpentine-rich marble or verde antique, valued for its rich green color and white veining.

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