Rock & Mineral Encyclopedia

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

Zebra Jasper

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

A black manganese dioxide mineral that is the most important ore of manganese and a source of black pigment and dendrites.

A translucent apple-green chalcedony colored by nickel, the most prized green variety of the quartz family.