Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Pastel Obsidian
Soft pastel-colored glass sold as obsidian; multicolor pastel material is manufactured art glass rather than natural volcanic obsidian.
igneousPrase
An old name for a dull leek-green variety of quartz or chalcedony colored by green mineral inclusions, historically called mother of emerald.
crystalAmegreen
A natural bicolor quartz blending amethyst purple with prasiolite green in a single crystal, prized as a metaphysical heart-crown stone.
crystal
Greensand
A green, glauconite-rich marine sandstone that records slow deposition on continental shelves and is used as a soil amendment.
sedimentary
Malachite
A vivid green copper carbonate mineral famous for swirling concentric bands, used as an ore of copper and an ornamental gemstone.
mineralRoyal Blue Obsidian
A deep royal-blue glass sold as obsidian; the rich blue body color is manufactured, unlike natural blue-sheen obsidian whose blue is only a surface effect.
igneousMint Garnet
A delicate pastel-green grossular garnet, lighter than tsavorite, most famously from the Merelani Hills of Tanzania.
gemstone
Pyromorphite
A lead phosphate secondary mineral known for barrel-shaped green to yellow crystals formed in oxidized lead deposits.
mineral
Limburgite
A dark, glass-rich volcanic rock of olivine and augite phenocrysts set in a feldspar-free glassy groundmass, named from the Kaiserstuhl region.
igneous
Pitchstone
A dull, resinous volcanic glass similar to obsidian but with higher water content and a waxy pitch-like luster.
igneousGolden Peacock Obsidian
A natural sheen obsidian showing a warm gold shimmer plus peacock iridescence, caused by aligned nanoparticle layers within black glass.
igneous
Verdite
A rich green, fuchsite-rich metamorphic rock from southern Africa, prized as a carving and ornamental stone.
metamorphic
Blue Beryl
The blue color variety of beryl, ranging from pale sky tones to rich sea-blue, best known in its finest grades as aquamarine.
gemstone
Glauconite
A soft, green iron-potassium mica that forms in marine sediments and gives greensand its characteristic olive color.
mineral
Verdelite
The classic green gem variety of elbaite tourmaline, ranging from bright grass-green to deep forest tones colored by iron or chromium.
gemstone
Peacock Opal
A precious opal showing dominant peacock-like blue, green and teal play-of-color, often on Ethiopian material.
gemstone
Chrysoprase
A translucent apple-green chalcedony colored by nickel, the most prized green variety of the quartz family.
gemstone
Chlorite Schist
A soft, green, foliated rock rich in chlorite, formed by low-grade metamorphism of mafic or volcanic rocks.
metamorphicGooseberry Garnet
Gooseberry Garnet is a soft green grossular garnet named for its resemblance to the pale, translucent green of ripe gooseberries.
gemstone
Teal Tourmaline
A sought-after elbaite tourmaline in teal hues that blend blue and green, prized for its ocean-like color.
gemstone
Chrome Tourmaline
An intensely green tourmaline colored by chromium and vanadium, prized for its vivid emerald-like color from East Africa.
gemstone
Silver Sheen Obsidian
Black volcanic glass displaying a silvery shimmer from light reflecting off aligned microscopic gas bubbles trapped in the obsidian.
crystal
Red Obsidian
Volcanic glass tinted red by fine iron-oxide inclusions, often blended with black to form mahogany-patterned obsidian.
crystal
Merelani Mint Garnet
A delicate vanadium-colored mint-green grossular garnet from the Merelani Hills of Tanzania, the source of tanzanite.
gemstone