Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Skarn
A calc-silicate rock formed by chemical exchange between magma and carbonate rock, often rich in garnet and economically important ore minerals.
metamorphic
Wolframite
Wolframite is the historic principal ore of tungsten, a heavy black tungstate forming bladed crystals in granite veins.
mineral
Bronzite
An iron-rich orthopyroxene prized for its warm bronze schiller, a metallic-looking sheen created by tiny mineral inclusions.
mineral
Websterite
A variety of pyroxenite composed of both orthopyroxene and clinopyroxene with little olivine, found in layered intrusions and the mantle.
igneous
Minette
A dark, mica-rich lamprophyre dike rock in which biotite and augite phenocrysts sit in a groundmass dominated by alkali feldspar.
igneousChrome Spessartine
Chrome Spessartine is a rare chromium-bearing manganese garnet whose trace chromium intensifies its already vivid orange color.
gemstoneSunset Tourmaline
A warm-hued tourmaline blending orange, pink and red tones reminiscent of a sunset sky.
gemstoneFrost Agate
A pale chalcedony agate with cloudy, frost-like white patterning suggesting frost on a window or icy crystalline textures.
gemstone
Flame Agate
A chalcedony agate with red, orange, and yellow plume or banding patterns that rise like dancing flames within the stone.
gemstone
Cathedral Agate
A banded agate whose internal structures resemble cathedral spires, arches, or a city skyline of towers and pinnacles.
gemstone
Lamproite
A rare ultrapotassic, magnesium-rich volcanic rock from deep in the mantle, famous as the diamond host at Argyle in Australia.
igneous
Bastnasite
A rare-earth fluorocarbonate that is one of the world's most important ores of cerium, lanthanum, and other rare earth elements.
mineral
Zincite
A rare zinc oxide best known for its deep red to orange color, classically from Franklin, New Jersey, and as colorful man-made crystals.
mineralCarver Agate
A collectible Oregon plume and scenic agate with feathery red and gold inclusions suspended in translucent chalcedony.
gemstone
Tactite
A contact-metasomatic calc-silicate rock, essentially a skarn, formed where intrusions react with carbonate rocks and often host ore.
metamorphic
Feather Agate
A translucent chalcedony agate containing delicate, feather- or plume-shaped mineral inclusions that branch like soft feathers.
gemstone
Shadow Agate
A banded agate that displays a moving shadow or flash across its surface when tilted under light, caused by closely spaced parallel bands.
gemstoneDragon Blood Jasper
A green-and-red ornamental stone of epidote and red piemontite or iron oxide, named for its dragon-skin coloring; not a true jasper.
metamorphic
Pelitic Schist
A schist derived from clay-rich sediments, rich in mica and often bearing index minerals like garnet, staurolite, or kyanite.
metamorphic
Brookite
An orthorhombic titanium dioxide polymorph forming tabular brown to black crystals with brilliant metallic-adamantine luster.
mineral
Honey Garnet
A warm golden-brown garnet named for its honey color, typically a hessonite grossular variety with a distinctive treacly internal texture.
gemstoneMalaia Garnet
A pyrope-spessartine garnet in warm peach, salmon, and pinkish-orange tones, originally rejected by dealers and named 'malaia,' Swahili for outcast.
gemstone
Harzburgite
A depleted mantle peridotite of olivine and orthopyroxene, the refractory residue left after basaltic melt is extracted from the mantle.
igneous
Peach Garnet
A soft peach to pinkish-orange garnet, usually a malaia-type pyrope-spessartine blend prized for its warm, delicate color.
gemstone