Rock & Mineral Encyclopedia

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

Carnelian

A warm orange-to-red variety of chalcedony quartz colored by iron oxide, used since antiquity for seals, beads, and cabochons.

A warmly colored chalcedony agate with reds, oranges, golds, and pinks that blend like the glowing bands of a sunset sky.

A group of silicate gemstones best known for deep red but spanning nearly every color, including green tsavorite and orange spessartine.

Glacially transported banded agates found along Lake Huron's shores, typically small, frosted pebbles with red-orange iron banding.

A glacier-transported banded agate from the Lake Superior region, colored by iron into rich reds and oranges, and Minnesota's state gemstone.

A red-toned banded chalcedony colored by iron oxides, ranging from natural carnelian-like reds to heat-treated stones.

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

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

An orbicular jasper with red and orange flower-like spots resembling poppies, famously from Morgan Hill, California.