Rock & Mineral Encyclopedia

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

Turritella Jasper

A fossiliferous jasper packed with spiral snail shells, technically a silicified gastropod limestone from Wyoming.

An opaque jasper from the Cave Creek area of Arizona, prized for earthy mottled and banded patterns in warm desert tones.

A rare, intensely blue chalcedony colored by copper-rich chrysocolla, prized as the most valuable of the blue chalcedonies.

A multicolored orbicular chalcedony from Madagascar famous for its circular eye-like orbs in greens, pinks, whites, and yellows.

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

Quartz containing a sealed pocket of ancient water, often with a mobile air bubble that moves when the crystal is tilted.

A vivid yellow-and-black banded stone from Indonesian volcanic vents, colored by sulfur, arsenic minerals and iron oxides, not true jasper.

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

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

A common opal containing moss- or fern-like mineral inclusions that resemble plants suspended in a pale silica body.

Ancient wood whose organic tissue has been replaced by silica, preserving the grain, rings, and structure of the original tree in stone.

A translucent, soft blue variety of microcrystalline quartz whose color comes from light scattering through its fine structure.

The classic gem opal that flashes shifting spectral colors, defined by the diffraction effect known as play-of-color.