Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Tiger Iron
A banded combination rock of golden tiger's eye, red jasper, and metallic hematite, formed in ancient iron deposits.
metamorphic
Rutilated Quartz
Clear or smoky quartz threaded with golden to reddish needles of rutile, also poetically called Venus hair stone.
crystal
Dravite
The magnesium-rich brown member of the tourmaline group, named for Austria's Drava River and prized for warm earthy tones.
mineral
Reedmergnerite
A rare boron-bearing feldspar, the boron analogue of albite, first found in oil-shale nodules of the Green River Formation.
mineral
Blue Pearl Granite
A Norwegian larvikite dimension stone prized for its shimmering blue iridescent feldspar crystals.
igneous
Sonoran Sunset Jasper
A vivid copper-bearing Mexican stone of red cuprite and green chrysocolla that evokes a desert sunset.
mineral
Leopard Opal
A patterned common opal with mottled, leopard-like spots and blotches, prized as an ornamental and cabochon stone.
gemstone
Indian Agate
An affordable multicolored banded and mossy chalcedony from India, common in tumbled stones, beads, and meditation pieces.
gemstone
Green Agate
A green-hued banded chalcedony, ranging from natural soft greens to brightly dyed commercial stones.
gemstone
Fireworks Obsidian
Black volcanic glass dotted with radiating spherulite bursts that look like exploding fireworks frozen in the stone.
igneous
Demantoid Garnet
A rare green andradite garnet famed for fire exceeding diamond and distinctive horsetail inclusions in Russian stones.
gemstone
Alabaster
A soft, fine-grained, translucent form of gypsum (or banded calcite) long prized as a carving and ornamental stone.
mineral
White Agate
A white to grayish banded chalcedony, the natural base color of much agate and the substrate for many dyed stones.
gemstone
Scenic Agate
A translucent agate whose mineral inclusions resemble miniature landscapes of trees, hills, and horizons within the stone.
gemstone
Purple Tourmaline
An uncommon purple to violet tourmaline colored by manganese, the deeper reddish-purple stones sometimes called siberite.
gemstone
Blood Agate
A deep red banded agate colored by iron oxides, valued as a vivid red lapidary and jewelry stone.
gemstone
Lemurian Seed Quartz
Clear quartz crystals marked by distinctive horizontal ladder-like striations, popularized from Brazil as a metaphysical stone.
crystal
Yellow Agate
A yellow to golden banded chalcedony colored by iron, ranging from natural honey tones to dyed commercial stones.
gemstone
Orbicular Granite
A rare granitic rock containing concentric, onion-like spheres called orbicules, prized as a striking ornamental stone.
igneous
Onyx Marble
Translucent banded calcium-carbonate stone deposited in caves and springs, prized for ornamental carvings despite its softness.
sedimentary
Labradorite
A plagioclase feldspar famous for labradorescence, a dramatic flash of iridescent blue, green, and gold across a dark gray stone.
mineral
Flash Opal
A precious opal whose play-of-color appears as broad rolling flashes of spectral color that shift as the stone moves.
gemstone
Yellow Tourmaline
Bright yellow to golden tourmaline colored by manganese, with the most vivid canary stones among the rarest tourmaline hues.
gemstone
Landscape Opal
A common opal containing dendritic or mossy mineral inclusions that form miniature landscape-like scenes inside the stone.
gemstone