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
Bixbyite
A black metallic manganese iron oxide famous for sharp cubic crystals, classically found with red beryl and topaz in Utah rhyolite.
mineral
Ruin Marble
A fractured fine-grained limestone whose iron-stained crack networks form natural scenes resembling ruined cities and landscapes.
sedimentary
Bloodstone
A dark green chalcedony speckled with blood-red spots of iron oxide, traditionally known as heliotrope.
gemstone
Dragon 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
Andradite Garnet
The calcium-iron garnet species, ranging from brilliant green demantoid to golden topazolite and jet-black melanite.
gemstone
Schorl
The common iron-rich black variety of tourmaline, by far the most abundant tourmaline species and a popular grounding crystal.
mineral
Eulysite
A rare, dense iron-rich metamorphic rock composed of fayalite, iron pyroxene, and almandine garnet.
metamorphic
Black Tourmaline
The opaque black iron-rich variety of tourmaline (schorl), forming striated prismatic crystals popular as a protective grounding stone.
mineral
Mocha Agate
A pale translucent chalcedony threaded with brown-black manganese and iron dendrites that mimic tiny ferns, mosses or landscapes.
gemstone
Kambaba Jasper
A dark green-and-black stromatolite jasper patterned with swirling orbs, formed from fossilized ancient microbial colonies.
sedimentary
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
Sard
A brownish-red to deep brown variety of chalcedony, closely related to carnelian but darker, colored by iron oxides.
mineral
Autumn Jasper
A warm-toned jasper named for its autumn-leaf palette of browns, rust, gold, and cream, popular as soothing earth-tone beads.
mineral
Bloodstone Jasper
A dark green jasper-chalcedony speckled with red iron-oxide spots, classically known as bloodstone or heliotrope.
mineral
Maligano Jasper
A rare Indonesian jasper from Sulawesi known for ghostly tube structures, brecciated patterns, and contrasting grey, red, and purple zones.
mineral
Pyrrhotite
A bronze-colored iron sulfide notable for being the most magnetic of the common sulfide minerals and an important nickel host.
mineral
Columbite
A black iron-manganese niobate that is a primary ore of niobium, forming a continuous series with tantalite (together called coltan).
mineral
Outback Jasper
An earthy Australian-style jasper in red, ochre, and yellow tones evoking the colors of the Outback desert.
mineral
Pumice
A frothy, lightweight volcanic glass so full of gas bubbles that it can float on water.
igneous
Novaculite
An extremely fine-grained, dense siliceous rock famous as Arkansas whetstone, prized for sharpening fine cutting tools.
sedimentary
Tantalite
A dense black iron-manganese tantalate that is the chief ore of tantalum, forming a series with columbite and mined as coltan.
mineral
Cave Creek Jasper
An opaque jasper from the Cave Creek area of Arizona, prized for earthy mottled and banded patterns in warm desert tones.
mineral
Soapstone
A soft, talc-rich metamorphic rock with a soapy feel, easily carved and highly heat-resistant for cookware and sculpture.
metamorphic