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.

Clear or smoky quartz threaded with golden to reddish needles of rutile, also poetically called Venus hair stone.

A common potassium feldspar identical in composition to orthoclase but more ordered, famous for its green gem variety amazonite.

A group of silicate gemstones best known for deep red but spanning nearly every color, including green tsavorite and orange spessartine.

Translucent banded calcium-carbonate stone deposited in caves and springs, prized for ornamental carvings despite its softness.

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

A white chalcedony filled with green or black dendritic, tree-like mineral inclusions that resemble ferns or moss frozen in stone.

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

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

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

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

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

A common opal containing dendritic or mossy mineral inclusions that form miniature landscape-like scenes inside the stone.

Quartz colored blue by inclusions of the mineral dumortierite, giving a denim-like blue ornamental stone harder than dumortierite alone.

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