Rock & Mineral Encyclopedia

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

Riband Agate

A banded chalcedony with straight, ribbon-like parallel layers, often cut across the bands for striking striped cabochons.

A precious opal showing dominant peacock-like blue, green and teal play-of-color, often on Ethiopian material.

An earthy-toned jasper with vine-like or scenic patterning, valued by lapidaries for warm browns, reds, and creams that polish to a smooth finish.