Rock Identifier

Rock & Mineral Encyclopedia

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

Verdelite

Verdelite

The classic green gem variety of elbaite tourmaline, ranging from bright grass-green to deep forest tones colored by iron or chromium.

gemstone
Serpentinite

Serpentinite

A green, often mottled metamorphic rock formed by the hydration of mantle rocks, soft and waxy with a smooth, slippery feel.

metamorphic
Grossular Garnet

Grossular Garnet

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

gemstone
Nephrite

Nephrite

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

gemstone
Hydrogrossular Garnet

Hydrogrossular Garnet

A water-bearing massive grossular garnet, usually green or pink, widely used as a tough jade-like carving stone.

gemstone
Chrysoprase

Chrysoprase

A translucent apple-green chalcedony colored by nickel, the most prized green variety of the quartz family.

gemstone
Amazonite

Amazonite

The blue-green gem variety of microcline feldspar, often mottled with white, prized as an affordable ornamental stone.

mineral
Microcline

Microcline

A common potassium feldspar identical in composition to orthoclase but more ordered, famous for its green gem variety amazonite.

mineral
Mariposite

Mariposite

A green, gold-associated metamorphic rock made of chrome-rich mica and quartz, named for Mariposa County in California's gold country.

metamorphic

Peruvian Blue Opal

A translucent common opal from the Andes prized for its serene blue to blue-green color, usually cut into cabochons and beads.

gemstone
Sapphire

Sapphire

The gem variety of corundum in every color except red, most prized in velvety blue and exceptionally hard and durable.

gemstone
Yellow Garnet

Yellow Garnet

A trade term for yellow garnets, including golden grossular, yellow andradite (topazolite), and yellow-green Mali garnet.

gemstone

Grandite Garnet

Grandite is an intermediate garnet between grossular and andradite, common in skarns and prized for vivid green to golden crystals.

mineral
Mylonite

Mylonite

A fine-grained, strongly foliated rock formed deep in fault zones where rocks flowed and ground down rather than fracturing.

metamorphic
Topazolite Garnet

Topazolite Garnet

A rare yellow to golden variety of andradite garnet, the topaz-colored cousin of green demantoid, prized for high dispersion and brilliance.

gemstone
Kakortokite

Kakortokite

A spectacularly banded agpaitic nepheline syenite of alternating red eudialyte, black amphibole and white feldspar layers from Ilimaussaq, Greenland.

igneous
Color Change Garnet

Color Change Garnet

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

gemstone
Ceylon Garnet

Ceylon Garnet

Ceylon Garnet is a historic trade name for fine red almandine (and hessonite) garnet from the gem gravels of Sri Lanka.

gemstone

Sunset Tourmaline

A warm-hued tourmaline blending orange, pink and red tones reminiscent of a sunset sky.

gemstone
Copper-Bearing Tourmaline

Copper-Bearing Tourmaline

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

gemstone
Cinnabar

Cinnabar

A bright red mercury sulfide, the chief ore of mercury and the historic source of the pigment vermilion.

mineral
Paraiba Tourmaline

Paraiba Tourmaline

An intensely glowing copper-bearing tourmaline famed for its electric neon blue-green color and extreme rarity and value.

gemstone

Pink Opal

A soft pink common opal, most famously from Peru, valued for its gentle pastel color rather than play-of-color.

gemstone

Regency Rose Agate

A prized plume agate with rose-pink and red feathery inclusions suspended in clear chalcedony, from the western U.S.

gemstone