Rock & Mineral Encyclopedia

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

Geode

A hollow rock nodule whose interior cavity is lined with inward-pointing crystals such as quartz, amethyst, or calcite.

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

Clusters of tiny botryoidal chalcedony spheres resembling bunches of grapes, famously purple, found in Indonesia.

A rare brown chalcedony containing thin iron-oxide layers that produce flashing, fiery rainbow iridescence like trapped flames.

A soft pink banded chalcedony, occurring naturally in delicate hues and also commonly produced by dyeing.

A nodular rhyolite geode-like ball whose plain exterior hides a star-shaped agate or chalcedony core when cut.

A translucent chalcedony agate whose mineral inclusions form miniature scenes resembling mountains, trees, deserts, and skies.

A chalcedony agate filled with radiating needle-like mineral inclusions, prized for its starburst and spray patterns.

A chalcedony agate with soft, billowing cloud-like masses of gray and white suspended in a translucent body.

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

Agate containing radiating sprays of mineral needles that fan out like bursting stars within the chalcedony.

A pale chalcedony agate with cloudy, frost-like white patterning suggesting frost on a window or icy crystalline textures.

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

A translucent chalcedony agate containing delicate, feather- or plume-shaped mineral inclusions that branch like soft feathers.

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