Rock & Mineral Encyclopedia

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

Lake Michigan Agate

Glacially deposited banded agates found along Lake Michigan beaches, small waterworn pebbles with concentric red and grey banding.

A vividly swirling banded agate from northern Mexico with intricate looping patterns in warm reds, golds and creams.

A vividly banded fortification agate from Argentina prized for its bold red, gold and white concentric patterns.

A translucent chalcedony from Montana filled with black and red dendritic inclusions that look like moss, ferns, or scenic landscapes.