Rock & Mineral Encyclopedia

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

Turquoise

A prized blue to blue-green copper-aluminium phosphate, often veined with dark matrix, treasured for jewelry across many cultures.

A soft pale-blue calcium sulfate, the anhydrous form of gypsum, prized as a gentle, calming tumbled stone.

A pale jasper crossed by distinctive blue-gray veins or lines, valued by lapidaries for its calm color contrast.

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

An opaque blue variety of chalcedony jasper, less common than red or green forms, colored by mineral inclusions.

An affordable multicolored banded and mossy chalcedony from India, common in tumbled stones, beads, and meditation pieces.

A common opal containing dendritic or mossy mineral inclusions that form miniature landscape-like scenes inside the stone.

A soft mint-to-apple-green variety of calcite, a common calcium carbonate mineral popular as soothing tumbled stones.

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

A golden-toned opal ranging from translucent common opal to precious stones flashing color against a warm yellow body.

A warm golden-to-amber opal ranging from translucent common opal to precious stones that flash play-of-color over a honey body.