Rock & Mineral Encyclopedia

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

Pyroxenite

A dense, dark ultramafic plutonic rock composed almost entirely of pyroxene minerals, often associated with peridotite and layered intrusions.

A sandstone in which the dominant grains are fragments of pre-existing rocks rather than single minerals, signaling rapid erosion nearby.

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

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

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

A calc-silicate rock formed by chemical exchange between magma and carbonate rock, often rich in garnet and economically important ore minerals.

A rare black carbon-rich rock from Russia, noted for containing fullerenes and ranging from dull mineralized stone to lustrous noble shungite.

A metamorphosed banded iron formation of alternating quartz and iron-oxide layers, mined as a major iron ore.

A banded, metamorphosed iron formation in which bright red jasper alternates with silvery hematite or magnetite layers.

A banded chalcedony agate with bold alternating dark and light stripes resembling zebra markings, sometimes color-enhanced.

A spectacularly banded agpaitic nepheline syenite of alternating red eudialyte, black amphibole and white feldspar layers from Ilimaussaq, Greenland.

Ancient chemically deposited rock of alternating iron-oxide and silica bands recording Earth's early oxygenation and a major iron ore source.

An old name for cesium-rich, often pink beryl (related to morganite), named after Russian mineralogist Victor Vorobyev.

The colorless to milky-white variety of beryl, known mineralogically as goshenite and once used to imitate diamond and other gems.