Rock & Mineral Encyclopedia

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

Dumortierite Quartz

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

An opaque, iron-rich variety of microcrystalline quartz known for its deep brick-red color and ancient history as a stone of strength and grounding.

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

Obsidian formed from two merged lava flows, producing a stone with two distinct bands of sheen or color.

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

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

A chalcedony agate with red, orange, and yellow plume or banding patterns that rise like dancing flames within the stone.

A white, porous borate mineral webbed with gray-black veins, widely dyed to imitate turquoise and other stones.

Bright yellow to golden tourmaline colored by manganese, with the most vivid canary stones among the rarest tourmaline hues.

A translucent agate whose mineral inclusions resemble miniature landscapes of trees, hills, and horizons within the stone.

A single beryl crystal showing two distinct color zones, such as aquamarine blue grading into morganite pink, within one stone.