Rock & Mineral Encyclopedia

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

Imperial Garnet

A trade name for high-brilliance golden grossular-andradite (grandite) garnet, most associated with the Mali deposits of West Africa.

A rare grossular-andradite blend ('grandite') from Mali, prized for its high brilliance and golden-green to yellow color.

Small, intensely red chrome-pyrope garnets from the Czech Bohemian region, famous for densely set antique Victorian jewelry.

Abundant banded chalcedony from southern Brazil, the world's main source of agate slices and dyed agate products.

Molybdenite is the primary ore of molybdenum, a soft, greasy, silver-gray sulfide that closely resembles graphite.

A hard zinc-rich member of the spinel group, usually dark blue-green to black, forming octahedral crystals in metamorphic and pegmatitic rocks.

A hydrated volcanic glass with pearly, onion-like concentric cracks that pops into lightweight white granules when heated.