Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Turquoise
A prized blue to blue-green copper-aluminium phosphate, often veined with dark matrix, treasured for jewelry across many cultures.
mineral
Bloodstone
A dark green chalcedony speckled with blood-red spots of iron oxide, traditionally known as heliotrope.
gemstone
Moonstone
A feldspar gem famous for adularescence, a floating blue-white glow that shimmers across the stone like moonlight.
gemstoneRainbow Moonstone
A near-colorless feldspar showing blue and multicolored sheen; gemologically a white labradorite rather than true orthoclase moonstone.
gemstone
Amazonite
The blue-green gem variety of microcline feldspar, often mottled with white, prized as an affordable ornamental stone.
mineralUnakite Jasper
An altered granite of pink feldspar, green epidote and quartz, mottled pink-and-green and popular as a tumbled and carving stone.
metamorphic
Chrysocolla
A vivid blue-green hydrated copper silicate, soft on its own but prized as a gem when hardened by intergrown quartz or chalcedony.
mineral
White Moonstone
The classic moonstone: a milky-white feldspar showing the prized floating blue-to-silver adularescent glow that gives the gem its name.
gemstone
Lake Michigan Agate
Glacially deposited banded agates found along Lake Michigan beaches, small waterworn pebbles with concentric red and grey banding.
gemstone
Flint
A hard, dark variety of chert that knaps into razor-sharp edges and sparks against steel, central to Stone Age technology.
sedimentaryGrey Moonstone
A smoky gray feldspar moonstone, often called new moon stone, showing a silvery-blue adularescent sheen over a translucent gray body.
gemstone
Iolite
The gem variety of cordierite, famous for strong pleochroism that shifts from violet-blue to near-colorless.
gemstone
Bloodstone Jasper
A dark green jasper-chalcedony speckled with red iron-oxide spots, classically known as bloodstone or heliotrope.
mineral
Green Agate
A green-hued banded chalcedony, ranging from natural soft greens to brightly dyed commercial stones.
gemstone
Yellow Agate
A yellow to golden banded chalcedony colored by iron, ranging from natural honey tones to dyed commercial stones.
gemstone
Kambaba Jasper
A dark green-and-black stromatolite jasper patterned with swirling orbs, formed from fossilized ancient microbial colonies.
sedimentary
Magnesite
A magnesium carbonate mineral, usually chalky white with grey veining, widely dyed to imitate turquoise and other stones.
mineral
Dumortierite Quartz
Quartz colored blue by inclusions of the mineral dumortierite, giving a denim-like blue ornamental stone harder than dumortierite alone.
gemstoneSesame Jasper
A finely speckled pale jasper trade stone named for its sesame-seed-like flecks, closely related to Kiwi Jasper.
mineral
Howlite
A white, porous borate mineral webbed with gray-black veins, widely dyed to imitate turquoise and other stones.
mineral
Orange Calcite
A soft, glowing orange variety of calcite colored by iron oxides, popular as tumbled stones and known for fizzing in acid.
mineralSpiderweb Jasper
A jasper crossed by fine dark veins forming a spiderweb-like network, often a brecciated stone cemented by darker matrix.
mineral
Scheelite
Scheelite is a calcium tungstate ore of tungsten, famous for its brilliant blue-white fluorescence under ultraviolet light.
mineral
Red Agate
A red-toned banded chalcedony colored by iron oxides, ranging from natural carnelian-like reds to heat-treated stones.
gemstone