Rock & Mineral Encyclopedia

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

Bloodstone

A dark green chalcedony speckled with blood-red spots of iron oxide, traditionally known as heliotrope.

A soft sky-blue chalcedony from the Owyhee region of Oregon and Idaho, prized for its calming, opaque powder-blue color.

An agate whose layered, segmented banding resembles the jointed stalks and leaves of bamboo.

A banded chalcedony with straight, ribbon-like parallel layers, often cut across the bands for striking striped cabochons.

A prized plume agate from near Carey, Idaho, showing red, pink and black feathery plumes floating in translucent chalcedony.

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

An affordable multicolored banded and mossy chalcedony from India, common in tumbled stones, beads, and meditation pieces.

A brown fossiliferous chalcedony packed with spiral freshwater snail shells, technically agatized fossil rock from Wyoming.

A lead molybdate mineral famous for thin, brilliant orange to yellow tabular crystals, prized by collectors and an ore of molybdenum.

A soft peachy-orange variety of banded chalcedony, naturally iron-tinted or dyed, popular for warm-toned beads and jewelry.

A translucent to transparent opal in warm yellow, orange, and red tones, prized for body color rather than play-of-color.

A translucent chalcedony from Montana filled with black and red dendritic inclusions that look like moss, ferns, or scenic landscapes.

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