Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Aquamarine
The serene blue-to-sea-green variety of beryl, aquamarine is a durable gemstone colored by trace iron and birthstone for March.
gemstoneChlorite 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.
gemstoneTeal Tourmaline
A sought-after elbaite tourmaline in teal hues that blend blue and green, prized for its ocean-like color.
gemstoneChrome Tourmaline
An intensely green tourmaline colored by chromium and vanadium, prized for its vivid emerald-like color from East Africa.
gemstoneMerelani Mint Garnet
A delicate vanadium-colored mint-green grossular garnet from the Merelani Hills of Tanzania, the source of tanzanite.
gemstoneTurquoise Obsidian
A vivid turquoise-blue glass sold as obsidian; this bright color is virtually always manufactured rather than natural volcanic glass.
igneousRainforest Jasper
An Australian green rhyolite with eye-like orbs and earthy patterns marketed as jasper, evoking dense rainforest foliage.
igneousAmazonite
The blue-green gem variety of microcline feldspar, often mottled with white, prized as an affordable ornamental stone.
mineralFrog Skin Jasper
A mottled green jasper whose blotchy spotting resembles frog skin, valued by lapidaries for its earthy, camouflage-like patterns.
gemstoneBamboo Agate
An agate whose layered, segmented banding resembles the jointed stalks and leaves of bamboo.
gemstoneOrange Calcite
A soft, glowing orange variety of calcite colored by iron oxides, popular as tumbled stones and known for fizzing in acid.
mineralBloodstone Jasper
A dark green jasper-chalcedony speckled with red iron-oxide spots, classically known as bloodstone or heliotrope.
mineralUnakite
An altered granite mottled pink and green from feldspar and epidote, popular as a tough, colorful ornamental rock.
metamorphicGreenschist
A green, foliated low-grade metamorphic rock colored by chlorite, actinolite, and epidote, marking the greenschist metamorphic facies.
metamorphicWatermelon Obsidian
A pink-and-green bicolor glass sold as obsidian; the watermelon coloring is manufactured and does not occur in natural volcanic glass.
igneousGarnierite
A vivid green hydrous nickel-magnesium silicate that is a major ore of nickel, mined from weathered ultramafic rocks.
mineralGreenstone
A general field term for green, low-grade metamorphosed basaltic rocks colored by chlorite, epidote, and actinolite.
metamorphicTeal Obsidian
A deep teal glass sold as obsidian; the saturated blue-green color is manufactured and not found in natural volcanic glass.
igneousMoldavite
A rare forest-green natural glass formed by a meteorite impact about 15 million years ago, found mainly in the Czech Republic.
gemstonePeridot
The gem-quality green variety of olivine, peridot is colored by iron and is one of the few gems found in only one color.
gemstoneDragon 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.
metamorphicKyanite
A bladed aluminosilicate famous for having two very different hardnesses depending on the direction you scratch it.
mineralWillemite
A zinc silicate famous for its brilliant green fluorescence under shortwave UV light, especially from Franklin, New Jersey.
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