Rock & Mineral Encyclopedia

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

Onyx

A banded variety of chalcedony quartz, classically black or black-and-white, long favored for cameos and beads.

A jasper marked with soft feather- or plume-like mineral inclusions that drift through a pale silica body.

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

A prized Oregon picture jasper from the Deschutes region known for soft scenic landscapes in cream, tan, and blue-gray.

An opaque patterned jasper named for its scaly, snakeskin-like surface markings of interlocking tan and brown cells.

A dark green chalcedony speckled with blood-red spots of iron oxide, traditionally known as heliotrope.

A gray-toned jasper with swirling cream, black, and brown leaf-like patterns, sometimes with druzy or agate pockets.

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

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

A translucent to transparent opal in warm yellow, orange, and red tones, prized for body color rather than play-of-color.