Rock & Mineral Encyclopedia

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

Cloud Agate

A chalcedony agate with soft, billowing cloud-like masses of gray and white suspended in a translucent body.

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

A translucent yellow-green silicate famous for its botryoidal 'grape' clusters, often hosting needle-like sprays of black epidote.