Rock & Mineral Encyclopedia

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

Brecciated Agate

Agate that was shattered and naturally re-cemented by silica, creating a mosaic of angular fragments in a quartz matrix.

A fractured and re-cemented agate whose angular broken bands resemble crumbling walls and ruined cityscapes when polished.

Tabular quartz crossed by a milky white thread-like line marking where the crystal repeatedly cracked and re-healed.