Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Honey Garnet
A warm golden-brown garnet named for its honey color, typically a hessonite grossular variety with a distinctive treacly internal texture.
gemstone
Red Beryl
An exceptionally rare red variety of beryl colored by manganese, found chiefly in Utah and prized as one of the rarest gems.
gemstone
Bubblegum Tourmaline
A bright, opaque-to-translucent bubblegum-pink elbaite tourmaline, a playful candy-pink variety popular in beads and cabochons.
gemstone
Hessonite Garnet
The cinnamon-to-honey colored variety of grossular garnet, prized in jewelry and revered as the gem 'gomed' in Vedic astrology.
gemstone
Oolitic Limestone
Limestone built from tiny rounded ooid grains resembling fish roe, formed in warm, agitated shallow seas.
sedimentary
Common Opal
Opal without play-of-color, valued for solid body hues; also called potch, it occurs in a wide range of colors worldwide.
gemstoneCat's Eye Opal
An opal cut to show chatoyancy, a sharp moving band of light like a cat's eye, usually in honey, green or yellow common opal.
gemstone
Smithsonite
Smithsonite is a zinc carbonate ore famous for glassy botryoidal crusts in blue-green, pink, and yellow hues.
mineral
Bone Opal
Fossil bone in which opal has replaced the original tissue, sometimes showing play-of-color, a rare collector fossil.
gemstone
Palagonite
A yellow-brown alteration material formed when basaltic volcanic glass reacts with water, common in hydrovolcanic tuffs and pillow lavas.
igneous
Cat's Eye Green Tourmaline
Green tourmaline cut as a cabochon to show a sharp moving band of light (chatoyancy) caused by fine parallel inclusions.
gemstone
Moldavite
A rare forest-green natural glass formed by a meteorite impact about 15 million years ago, found mainly in the Czech Republic.
gemstoneFlame Obsidian
Black volcanic glass that flashes flame-like bands of iridescent color when light strikes aligned nanoscale inclusions.
igneousSmoky Obsidian
Translucent smoky-gray obsidian that transmits a hazy light, intermediate between clear and fully black volcanic glass.
igneous
Cleavelandite
A striking platy, blade-like variety of albite feldspar that grows in fanned aggregates of thin white crystals within granite pegmatites.
mineral
Lemon Tourmaline
A bright lemon-to-canary yellow tourmaline colored by manganese, among the more cheerful and uncommon hues in the tourmaline family.
gemstone
Blue Beryl
The blue color variety of beryl, ranging from pale sky tones to rich sea-blue, best known in its finest grades as aquamarine.
gemstone
Rossmanite
A rare lithium-aluminum tourmaline with a vacant X site, typically pale pink to colorless and found in lithium pegmatites.
mineral
Cat's Eye Tourmaline
Tourmaline displaying chatoyancy, a moving band of light caused by parallel tube-like inclusions, when cut as a cabochon.
gemstone
Paraiba Tourmaline
An intensely glowing copper-bearing tourmaline famed for its electric neon blue-green color and extreme rarity and value.
gemstone
Reedmergnerite
A rare boron-bearing feldspar, the boron analogue of albite, first found in oil-shale nodules of the Green River Formation.
mineral
Pineapple Opal
A rare opal pseudomorph from White Cliffs, Australia, formed as opal replaced clustered crystals into a pineapple-like shape.
gemstoneMint Opal
A soft mint-green variety of common opal, usually opaque and colored by trace copper or nontronite inclusions rather than play-of-color.
gemstone
Caliche
A hardened soil crust cemented by calcium carbonate, forming a tough whitish layer common in arid and semi-arid regions.
sedimentary