Rock & Mineral Encyclopedia

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

Peacock Opal

A precious opal showing dominant peacock-like blue, green and teal play-of-color, often on Ethiopian material.

An exceptionally rare red variety of beryl colored by manganese, found chiefly in Utah and prized as one of the rarest gems.

The green chromium- and vanadium-colored variety of beryl, one of the four classic precious gemstones renowned for its rich green color.

The calcium-aluminum garnet species spanning green tsavorite, cinnamon hessonite, and colorless leuco garnet — one of the most varied garnets.

An Australian silicified radiolarite jasper in warm mustard, red, burgundy, and cream earth tones, found only in Western Australia.

One of the two jade minerals, an amphibole prized for its extreme toughness and soft, waxy green hues used in carving for millennia.

A green, glauconite-rich marine sandstone that records slow deposition on continental shelves and is used as a soil amendment.

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

A limestone packed with visible shells and shell fragments, recording the accumulation of marine invertebrate remains on ancient sea floors.