Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Microcline
A common potassium feldspar identical in composition to orthoclase but more ordered, famous for its green gem variety amazonite.
mineral
Olive Tourmaline
An earthy olive to yellowish-green tourmaline, a muted green-brown gem variety colored by iron with subtle warm undertones.
gemstoneMacusanite
A rare translucent yellow-green volcanic glass from the Macusani region of Peru, valued by faceters and sometimes confused with tektites.
igneous
Chrome Chalcedony
A vivid green chalcedony colored by chromium, often called mtorolite, resembling chrysoprase but owing its color to chromium rather than nickel.
gemstone
Willemite
A zinc silicate famous for its brilliant green fluorescence under shortwave UV light, especially from Franklin, New Jersey.
mineralGooseberry Garnet
Gooseberry Garnet is a soft green grossular garnet named for its resemblance to the pale, translucent green of ripe gooseberries.
gemstone
Chalcedony
A waxy, translucent microcrystalline form of quartz that serves as the parent group for agate, jasper, carnelian, and onyx.
mineralGondite
A metamorphic rock made chiefly of manganese-rich spessartine garnet and quartz, formed from ancient manganese-bearing sediments.
metamorphic
Herkimer Diamond
Exceptionally clear, naturally double-terminated quartz crystals from Herkimer County, New York, prized for their diamond-like brilliance.
crystal
Granodiorite
A common coarse-grained intrusive rock like granite but richer in plagioclase than potassium feldspar.
igneous
Needle Tourmaline
Fine acicular (needle-like) tourmaline crystals, often black schorl, frequently seen as slender inclusions within clear quartz.
mineralSuper Seven
A trade name for quartz containing a combination of seven minerals including amethyst, smoky quartz, and cacoxenite, prized by collectors.
crystalDallasite Jasper
A green-and-white volcanic breccia from Vancouver Island, cemented by jasper and rich in epidote, popular as a regional lapidary stone.
gemstone
Watermelon Tourmaline
A striking color-zoned tourmaline with a pink center and green rind, resembling a slice of watermelon when cut across the crystal.
gemstoneTurquoise Obsidian
A vivid turquoise-blue glass sold as obsidian; this bright color is virtually always manufactured rather than natural volcanic glass.
igneous
Glauconite
A soft, green iron-potassium mica that forms in marine sediments and gives greensand its characteristic olive color.
mineralTeal Obsidian
A deep teal glass sold as obsidian; the saturated blue-green color is manufactured and not found in natural volcanic glass.
igneous
Ruby in Zoisite
A striking rock of green zoisite studded with red-pink ruby crystals and black hornblende, also called anyolite.
metamorphic
Andradite Garnet
The calcium-iron garnet species, ranging from brilliant green demantoid to golden topazolite and jet-black melanite.
gemstone
Transvaal Jade
A massive green-to-pink hydrogrossular garnet from South Africa used as a jade simulant, not a true jade.
gemstone
Chrome Diopside
A vivid green chromium-bearing diopside, an affordable emerald-like gem mined largely in Siberia.
gemstone
Bloodstone
A dark green chalcedony speckled with blood-red spots of iron oxide, traditionally known as heliotrope.
gemstoneDendritic Jasper
A pale jasper threaded with black, fern-like mineral dendrites that mimic plants, trees, and frost despite being inorganic.
mineral
Scenic Jasper
A patterned jasper whose bands and inclusions create miniature landscapes of deserts, mountains, and skies within the stone.
mineral