Rock & Mineral Encyclopedia

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

Moonstone

A feldspar gem famous for adularescence, a floating blue-white glow that shimmers across the stone like moonlight.

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

A precious opal showing dominant peacock-like blue, green and teal play-of-color, often on Ethiopian material.