Rock & Mineral Encyclopedia

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

Amazonite

The blue-green gem variety of microcline feldspar, often mottled with white, prized as an affordable ornamental stone.

A finely banded agate from Botswana known for delicate parallel layers of grey, pink, and white.

A dark gray-to-black feldspar variety of moonstone that shows blue and white adularescent flash against a smoky body.

A transparent to milky opal that displays a soft bluish-white internal glow or sheen that seems to follow the light source.

Ancient chemically deposited rock of alternating iron-oxide and silica bands recording Earth's early oxygenation and a major iron ore source.

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

A richly colored red banded agate prized by lapidaries for its deep crimson-to-brown tones reminiscent of pigeon's blood.