Rock & Mineral Encyclopedia

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

Jet

A lightweight black organic gemstone formed from fossilized wood under pressure, a type of lignite long used in mourning jewelry.

A trade name for deep, solid black obsidian, natural volcanic glass prized for its uniform jet-black color and glassy luster.

The darkest, near-opaque black variety of smoky quartz, colored by natural radiation acting on trace aluminum.

A solid jet-black chalcedony, usually a dyed and treated agate, prized for sleek polished beads, cabochons, and intaglios.

The calcium-iron garnet species, ranging from brilliant green demantoid to golden topazolite and jet-black melanite.

Jet-black natural volcanic glass formed by rapidly cooled lava, prized for its glassy luster and razor-sharp conchoidal fracture.

A glassy, jet-black volcanic rock formed when lava cools too fast to crystallize, prized for razor-sharp conchoidal edges.