Rock & Mineral Encyclopedia

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

Limestone

A soft carbonate sedimentary rock made mostly of calcite, often packed with marine fossils and prone to forming caves.

A banded jasper with cream, tan, and brown layers resembling snakeskin, often sourced from Madagascar.

A cream-colored spotted stone resembling a Dalmatian dog, made of feldspar and quartz dotted with dark mineral grains.

An orbicular jasper with red and orange flower-like spots resembling poppies, famously from Morgan Hill, California.

A chalcedony with a distinctive scaly, reptile-skin surface texture, typically in pale tan, pink, and gray tones.

A warm golden to amber translucent chalcedony agate whose color and glow resemble honey, sometimes with banding.

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

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

A rare agate that forms naturally with flat polygonal faces and angular geometric shapes rather than the usual rounded nodule.

A white, porous borate mineral webbed with gray-black veins, widely dyed to imitate turquoise and other stones.

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

The blue-grey relative of tiger's eye, a chatoyant quartz showing a shifting band of light like a bird of prey's eye.

A brecciated, chatoyant quartz with swirling blue, gold, and brown fibers that shimmer like a stormy sky.