Rock & Mineral Encyclopedia

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

Sardonyx

A banded chalcedony combining reddish-brown sard with white or black onyx layers, prized since antiquity for carved cameos.

A glacier-transported banded agate from the Lake Superior region, colored by iron into rich reds and oranges, and Minnesota's state gemstone.

A warmly colored chalcedony agate with reds, oranges, golds, and pinks that blend like the glowing bands of a sunset sky.

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

The official state rock of Kentucky, a banded agate famous for striking deep-red and black fortification patterns.

A collectible Oregon plume and scenic agate with feathery red and gold inclusions suspended in translucent chalcedony.

Plume and fortification agate from the famous Woodward Ranch near Alpine, Texas, known for red and pink plumes.

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

A celebrated plume agate from the Oregon-Idaho border, known for dramatic black, gold, and red plumes in clear chalcedony.

A brown fossiliferous chalcedony packed with spiral freshwater snail shells, technically agatized fossil rock from Wyoming.

Glacially deposited banded agates found along Lake Michigan beaches, small waterworn pebbles with concentric red and grey banding.

A vividly swirling banded agate from northern Mexico with intricate looping patterns in warm reds, golds and creams.

A vividly banded fortification agate from Argentina prized for its bold red, gold and white concentric patterns.

A translucent chalcedony from Montana filled with black and red dendritic inclusions that look like moss, ferns, or scenic landscapes.

A green-and-white volcanic breccia from Vancouver Island, cemented by jasper and rich in epidote, popular as a regional lapidary stone.