Rock & Mineral Encyclopedia

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

Shadow Agate

A banded agate that displays a moving shadow or flash across its surface when tilted under light, caused by closely spaced parallel bands.

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

An altered granite mottled pink and green from feldspar and epidote, popular as a tough, colorful ornamental rock.

A green-and-red ornamental stone of epidote and red piemontite or iron oxide, named for its dragon-skin coloring; not a true jasper.

Agate that forms in flat cracks or veins of host rock rather than rounded nodules, producing straight, parallel banding.

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

An Australian green rhyolite with eye-like orbs and earthy patterns marketed as jasper, evoking dense rainforest foliage.

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