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 jasper made of angular fragments naturally cemented back together, typically showing red and brown pieces in a quartz matrix.

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

A deep red banded agate colored by iron oxides, valued as a vivid red lapidary and jewelry stone.

A rare Australian jasper from the Pilbara with bold red, yellow, and black abstract patterns, prized by collectors.

An orange-to-rust colored variety of natural volcanic glass whose warm tone comes from iron oxide staining within the obsidian.

An opaque green variety of chalcedony quartz colored by iron and chlorite-group inclusions, prized as a durable carving and cabochon stone.

A dark green jasper-chalcedony speckled with red iron-oxide spots, classically known as bloodstone or heliotrope.

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

A foliated metamorphic rock dominated by quartz with enough mica to give it a schistose, splitting fabric.

A clean, mature sandstone made almost entirely of quartz grains, representing extreme weathering, sorting, and recycling of sediment.

An earthy olive to yellowish-green tourmaline, a muted green-brown gem variety colored by iron with subtle warm undertones.