Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Pyrite
The brassy iron sulfide mineral famous as 'fool's gold,' known for sharp metallic cubes and a much higher hardness than real gold.
mineral
Peacock Ore
A copper-iron sulfide ore famous for its iridescent peacock-like purple and blue tarnish; often sold as treated chalcopyrite.
mineral
Arsenopyrite
A silver-white iron arsenic sulfide and the most common arsenic mineral, known for striking sparks and a garlic smell when struck.
mineral
Chalcopyrite
A brassy copper-iron sulfide that is the world's most important copper ore, often showing colorful iridescent tarnish.
mineral
Pyrrhotite
A bronze-colored iron sulfide notable for being the most magnetic of the common sulfide minerals and an important nickel host.
mineral
Galena
A heavy, lead-grey metallic mineral with perfect cubic cleavage, galena is the world's main ore of lead and often carries silver.
mineral
Lapis Lazuli
An intensely blue metamorphic rock of lazurite flecked with golden pyrite, prized for millennia as a gemstone and ultramarine pigment.
metamorphicGondite
A metamorphic rock made chiefly of manganese-rich spessartine garnet and quartz, formed from ancient manganese-bearing sediments.
metamorphic
Bumblebee Jasper
A vivid yellow-and-black banded stone from Indonesian volcanic vents, colored by sulfur, arsenic minerals and iron oxides, not true jasper.
sedimentary
Banded Iron Formation
Ancient chemically deposited rock of alternating iron-oxide and silica bands recording Earth's early oxygenation and a major iron ore source.
sedimentary
Black Shale
Dark, organic-rich fine-grained sedimentary rock formed in oxygen-poor waters, often a source rock for oil and gas.
sedimentary
Millerite
A nickel sulfide famous for delicate brass-yellow hairlike crystals that form radiating sprays inside cavities and geodes.
mineralBekily Garnet
A rare color-change garnet from Bekily, Madagascar, shifting from bluish-green in daylight to purplish-red under warm light, including the famed blue garnets.
gemstone
Color Change Garnet
A rare garnet that dramatically shifts color from greenish in daylight to reddish under lamplight, rivaling alexandrite.
gemstone
Bohemian Garnet
Small, intensely red chrome-pyrope garnets from the Czech Bohemian region, famous for densely set antique Victorian jewelry.
gemstone
Ant Hill Garnet
Small, bright chrome-pyrope garnets famously brought to the surface by harvester ants on the Navajo lands of Arizona.
gemstone
Chrome Pyrope
A chromium-rich pyrope garnet whose intense blood-red color comes from chromium, often mined from ant hills and kimberlite weathering.
gemstoneMasasi Blue Garnet
Masasi Blue Garnet is a rare vanadium-bearing color-change garnet from Tanzania that appears blue-green by day and purplish-red indoors.
gemstone
Lindi Garnet
Lindi Garnet is a rare vanadium-rich color-change garnet from Tanzania's Lindi region, shifting from blue-green daylight tones to purple-red.
gemstone
Bismuthinite
A soft lead-gray bismuth sulfide that is an important ore of bismuth, forming metallic needle-like and bladed crystals.
mineral
Strawberry Garnet
A bright strawberry-red garnet, typically an almandine-pyrope blend prized for its juicy, lively red color in jewelry.
gemstoneArizona Ruby
Arizona Ruby is a chromium-rich pyrope garnet from Arizona, often gathered from anthills, valued for its intense ruby-like red.
gemstone
Bauxite
An earthy aluminum-rich residual rock and the world's principal ore of aluminum, often showing distinctive pea-like pisolites.
sedimentaryGrape Garnet
A trademarked deep purple-red rhodolite garnet from India, named for its rich grape-like color from the pyrope-almandine series.
gemstone