Rock & Mineral Encyclopedia

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

Dalmatian Jasper

A cream-colored spotted stone resembling a Dalmatian dog, made of feldspar and quartz dotted with dark mineral grains.

A limestone made of tiny spherical ooids, resembling fish roe, formed in warm, agitated shallow seas.

The golden-yellow variety of quartz, ranging from pale lemon to deep madeira amber, often produced by heating amethyst.

A glowing orange-to-red opal whose warm body color resembles flame; some stones add flashes of play-of-color.

A warm golden to amber translucent chalcedony agate whose color and glow resemble honey, sometimes with banding.

A pegmatitic granite in which quartz and feldspar intergrow to resemble ancient runic or Hebrew script.

A banded agate whose internal structures resemble cathedral spires, arches, or a city skyline of towers and pinnacles.

A green-and-black mottled jasper whose scale-like patterning resembles reptile skin, often linked to Kambaba and crocodile jaspers.

A jasper made of angular fragments naturally cemented back together, typically showing red and brown pieces in a quartz matrix.

A soft carbonate sedimentary rock made mostly of calcite, often packed with marine fossils and prone to forming caves.

A rare zinc oxide best known for its deep red to orange color, classically from Franklin, New Jersey, and as colorful man-made crystals.

A very fine-grained sedimentary rock made mostly of clay minerals, smooth to the touch and lacking the gritty feel of siltstone.