Rock & Mineral Encyclopedia

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

Blue Calcite

A soft, soothing powder-blue variety of calcite, a common calcium carbonate mineral often sold as gentle tumbled stones.

A natural bicolor quartz blending amethyst purple with prasiolite green in a single crystal, prized as a metaphysical heart-crown stone.

A creamy pink-and-white chalcedony from Madagascar containing flower-like plume inclusions that resemble blossoms suspended in stone.

Precious opal from the Mintabie field in South Australia, known for hard, bright crystal opal and some dark-bodied stones.