Rock & Mineral Encyclopedia

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

Needle Tourmaline

Fine acicular (needle-like) tourmaline crystals, often black schorl, frequently seen as slender inclusions within clear quartz.

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

A black volcanic glass threaded with delicate grey, swirling lace-like bands of flow lines that show beautifully when polished.