Rock & Mineral Encyclopedia

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

Adinole

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

The most common type of mantle peridotite, made of olivine with both orthopyroxene and clinopyroxene, representing fertile upper-mantle 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.

A schist derived from clay-rich sediments, rich in mica and often bearing index minerals like garnet, staurolite, or kyanite.

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

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

A dark, highly vesicular volcanic rock full of gas bubbles, denser than pumice, common as red or black lava rock.

A common potassium feldspar identical in composition to orthoclase but more ordered, famous for its green gem variety amazonite.

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

Rutile is a major titanium ore and the famous golden needle inclusion that gives rutilated quartz its shimmering threads.