Rock & Mineral Encyclopedia

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

Blue Jasper

An opaque blue variety of chalcedony jasper, less common than red or green forms, colored by mineral inclusions.

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

A chalcedony agate filled with radiating needle-like mineral inclusions, prized for its starburst and spray patterns.

Agate containing radiating sprays of mineral needles that fan out like bursting stars within the chalcedony.

A translucent, gelatinous-looking opal whose transparency gives floating, glowing play-of-color a watery, jelly-like appearance.