Rock & Mineral Encyclopedia

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

Shadow Agate

A banded agate that displays a moving shadow or flash across its surface when tilted under light, caused by closely spaced parallel bands.

A water-bearing massive grossular garnet, usually green or pink, widely used as a tough jade-like carving stone.

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

A fiery jasper whose red, orange, and yellow plumes lick across the stone like flames against an earthy background.

A green ornamental stone, often serpentine-rich marble or verde antique, valued for its rich green color and white veining.

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

Quartz colored blue by inclusions of the mineral dumortierite, giving a denim-like blue ornamental stone harder than dumortierite alone.

A white chalcedony filled with green or black dendritic, tree-like mineral inclusions that resemble ferns or moss frozen in stone.

A tourmaline displaying two or more distinct colors in a single crystal, prized for natural color zoning like watermelon and bicolor stones.