Rock & Mineral Encyclopedia

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

Bird's Eye Jasper

A microcrystalline quartz jasper marked by small concentric ring or eye patterns that resemble the eyes of birds.

A sedimentary rock built from pea-sized concentric spheres called pisoids, often carbonate but sometimes iron or aluminum-rich.

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

A fine-grained, sodium-rich contact-metasomatic rock formed where shale is albitized next to intruding diabase or spilite.

A vivid blue-green hydrated copper silicate, soft on its own but prized as a gem when hardened by intergrown quartz or chalcedony.

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

A pink, manganese-rich variety of zoisite used as an ornamental gemstone, often mottled with white quartz and grey matrix.