Rock & Mineral Encyclopedia

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

Pearl

An organic gem formed inside mollusks from layered nacre, prized for its iridescent luster and classic elegance.

A rare sky-blue variety of pectolite found only in the Dominican Republic, prized for its sea-like color and white volcanic patterning.

A rare garnet that dramatically shifts color from greenish in daylight to reddish under lamplight, rivaling alexandrite.

Tourmaline colored by copper, producing the famous vivid neon blues, greens and teals known commercially as Paraiba-type gems.

A colorful trade-name material, often dyed and reconstituted, sold as jasper; vivid blues and greens are typically artificially enhanced.

Vanadium-colored tourmaline, including the species vanadium dravite, producing rich emerald-green hues similar to chrome tourmaline.

A soft pale-blue calcium sulfate, the anhydrous form of gypsum, prized as a gentle, calming tumbled stone.

Scheelite is a calcium tungstate ore of tungsten, famous for its brilliant blue-white fluorescence under ultraviolet light.

A calcium-magnesium tourmaline that forms in metamorphosed limestones, typically dark green to brown and often in well-formed crystals.