Rock & Mineral Encyclopedia

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

Peruvian Blue Opal

A translucent common opal from the Andes prized for its serene blue to blue-green color, usually cut into cabochons and beads.

A colorful trade-name material, often dyed and reconstituted, sold as jasper; vivid blues and greens are typically artificially enhanced.