Rock & Mineral Encyclopedia

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

Dragon Blood Jasper

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 finely speckled pale jasper trade stone named for its sesame-seed-like flecks, closely related to Kiwi Jasper.

A dark green-and-black stromatolite jasper patterned with swirling orbs, formed from fossilized ancient microbial colonies.

A dark green jasper-chalcedony speckled with red iron-oxide spots, classically known as bloodstone or heliotrope.

A loose, wind-blown silt deposit, typically buff-colored and very fertile, that forms thick blankets and stands in steep cliffs.

A dark, layered agpaitic nepheline syenite rich in sodic pyroxene and amphibole with eudialyte, from the Lovozero and Ilimaussaq complexes.

A dark, mafic potassic alkaline rock rich in augite with alkali feldspar and often nepheline, classically forming the base of layered sills.

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

A dark, organic-rich shale loaded with kerogen and bitumen that can yield oil and gas, often finely laminated and combustible.

Tabular quartz crossed by a milky white thread-like line marking where the crystal repeatedly cracked and re-healed.

A black-and-white striped chalcedony-quartz rock whose bold zebra-like banding makes it a popular ornamental and lapidary stone.

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