Rock & Mineral Encyclopedia

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

Flame Agate

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

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

A vivid Australian jasper-like silica stone in earthy reds, yellows, and purples, formed from silicified radiolarian sediment.

A creamy pink-and-white chalcedony from Madagascar containing flower-like plume inclusions that resemble blossoms suspended in stone.

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

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.

A red-toned banded chalcedony colored by iron oxides, ranging from natural carnelian-like reds to heat-treated stones.

A black-and-white striped chalcedony-quartz rock whose bold zebra-like banding makes it a popular ornamental and lapidary stone.

A precious opal pattern made of tiny, densely packed pinpoint flashes of play-of-color, like sparkling speckles across the stone.

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

A precious opal showing dominant peacock-like blue, green and teal play-of-color, often on Ethiopian material.

A sought-after elbaite tourmaline in teal hues that blend blue and green, prized for its ocean-like color.

An intensely green tourmaline colored by chromium and vanadium, prized for its vivid emerald-like color from East Africa.

An opal cut to show chatoyancy, a sharp moving band of light like a cat's eye, usually in honey, green or yellow common opal.