Rock & Mineral Encyclopedia

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

Orange Tourmaline

A warm orange to tangerine tourmaline, an uncommon hue produced by manganese and iron in the crystal.

A natural volcanic glass with rich brown and black mahogany-like swirls created by iron oxide inclusions.

An orange-to-rust colored variety of natural volcanic glass whose warm tone comes from iron oxide staining within the obsidian.

A pale translucent chalcedony threaded with brown-black manganese and iron dendrites that mimic tiny ferns, mosses or landscapes.

Rounded nodules of translucent obsidian, named after a Native American legend, that glow smoky brown when held to light.

An opaque brown chalcedony whose iron-stained banding mimics deserts, dunes, and distant mountain skylines.

A coarse sedimentary rock of rounded pebbles and gravel cemented in a finer matrix, recording ancient rivers and beaches.

A conglomerate altered by heat and pressure, often with its rounded pebbles stretched and flattened into elongated lenses.

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

Iron-stained sandstone whose red color comes from hematite coatings, formed in oxidizing desert, river, and coastal environments.

A rare brown chalcedony containing thin iron-oxide layers that produce flashing, fiery rainbow iridescence like trapped flames.