Rock & Mineral Encyclopedia

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

Leopard Opal

A patterned common opal with mottled, leopard-like spots and blotches, prized as an ornamental and cabochon stone.

A sought-after elbaite tourmaline in teal hues that blend blue and green, prized for its ocean-like color.

A black volcanic glass threaded with delicate grey, swirling lace-like bands of flow lines that show beautifully when polished.