Rock & Mineral Encyclopedia

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

Yellow Opal

A cheerful yellow opal ranging from translucent common opal to golden fire opal, colored by trace iron in the silica.

A warm orange to tangerine tourmaline, an uncommon hue produced by manganese and iron in the crystal.

A warm golden-brown garnet named for its honey color, typically a hessonite grossular variety with a distinctive treacly internal texture.

A rare ultrapotassic, magnesium-rich volcanic rock from deep in the mantle, famous as the diamond host at Argyle in Australia.

A classic Oregon plume agate from the Priday Ranch beds, showing feathery mineral plumes suspended in translucent chalcedony.

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

A rare granitic rock containing concentric, onion-like spheres called orbicules, prized as a striking ornamental stone.

A multicolored orbicular chalcedony from Madagascar famous for its circular eye-like orbs in greens, pinks, whites, and yellows.

Fine, golden, hair-like strands of basaltic volcanic glass spun from fluid lava droplets during eruptions, named for the Hawaiian volcano goddess.

A trade term for yellow garnets, including golden grossular, yellow andradite (topazolite), and yellow-green Mali garnet.

Grandite is an intermediate garnet between grossular and andradite, common in skarns and prized for vivid green to golden crystals.

A hard, brilliant fluorosilicate gemstone occurring in many colors, from precious golden imperial topaz to popular blue topaz.

A banded combination rock of golden tiger's eye, red jasper, and metallic hematite, formed in ancient iron deposits.

An intensely blue metamorphic rock of lazurite flecked with golden pyrite, prized for millennia as a gemstone and ultramarine pigment.

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