Rock & Mineral Encyclopedia

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

Greenschist

A green, foliated low-grade metamorphic rock colored by chlorite, actinolite, and epidote, marking the greenschist metamorphic facies.

A general field term for green, low-grade metamorphosed basaltic rocks colored by chlorite, epidote, and actinolite.

A medium-grade metamorphic rock rich in aligned platy minerals that gives it a shiny, easily splitting, foliated texture.

A soft, green, foliated rock rich in chlorite, formed by low-grade metamorphism of mafic or volcanic rocks.

The classic green ornamental gem, either jadeite or nephrite, valued for millennia for its toughness and rich color, especially imperial green.

A tough, dark, medium-grained igneous rock with the composition of basalt, common in dikes and sills.

Basalt that has been metamorphosed, developing new minerals like chlorite, actinolite, and epidote that give it a greenish color.

A tough, prized ornamental gem that is actually two distinct minerals, jadeite and nephrite, revered for millennia in many cultures.

One of the two jade minerals, an amphibole prized for its extreme toughness and soft, waxy green hues used in carving for millennia.

A vivid green copper carbonate mineral famous for swirling concentric bands, used as an ore of copper and an ornamental gemstone.

A dark, foliated schist rich in needle-like hornblende crystals, formed by metamorphism of mafic igneous rocks.

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

A rich green, fuchsite-rich metamorphic rock from southern Africa, prized as a carving and ornamental stone.

An altered granite of pink feldspar, green epidote and quartz, mottled pink-and-green and popular as a tumbled and carving stone.

Sand-grained limestone composed of carbonate particles such as shell fragments and ooids cemented into a calcite rock.