Rock & Mineral Encyclopedia

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

Rutilated Quartz

Clear or smoky quartz threaded with golden to reddish needles of rutile, also poetically called Venus hair stone.

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

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

A Norwegian intrusive rock whose feldspar crystals flash silvery-blue, widely used as blue pearl granite countertops.

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

Extremely hard surface rock formed when silica cements soil and sediment into a tough duricrust in arid landscapes.

A brown fossiliferous chalcedony packed with spiral freshwater snail shells, technically agatized fossil rock from Wyoming.

A pegmatite rock of feldspar intergrown with wedge-shaped quartz that resembles ancient runic or Hebrew writing.

The highest-rank coal, a hard, lustrous black rock that burns cleanly with little smoke and high heat output.

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

A green ornamental stone, often serpentine-rich marble or verde antique, valued for its rich green color and white veining.

A red-toned banded chalcedony colored by iron oxides, ranging from natural carnelian-like reds to heat-treated stones.