Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Pink Emerald
A trade name sometimes used for pink beryl (morganite), the manganese-colored rose-to-peach variety of the emerald mineral.
gemstone
White Agate
A white to grayish banded chalcedony, the natural base color of much agate and the substrate for many dyed stones.
gemstone
White Garnet
The rare colorless-to-white grossular garnet, also called leuco garnet, prized by collectors for its purity and unusual lack of color.
gemstoneOrca Agate
A bold black-and-white banded chalcedony named for its orca-like coloring, popular as carvings and statement jewelry.
gemstone
Pink Tourmaline
A pink to red gem variety of elbaite tourmaline, colored by manganese, ranging from soft pastel pink to vivid rubellite red.
gemstone
White Obsidian
A pale, partly crystallized volcanic glass; genuinely white obsidian is uncommon and usually reflects devitrification or spherulitic growth in the glass.
igneousDallasite Jasper
A green-and-white volcanic breccia from Vancouver Island, cemented by jasper and rich in epidote, popular as a regional lapidary stone.
gemstone
Pegmatite
An exceptionally coarse-grained igneous rock, often granitic, famous for hosting large crystals and many gemstones.
igneous
White Moonstone
The classic moonstone: a milky-white feldspar showing the prized floating blue-to-silver adularescent glow that gives the gem its name.
gemstoneWhite Cliffs Opal
Precious opal from the historic White Cliffs field in New South Wales, Australia, famous for light opal and rare opal pineapples.
gemstone
Charnockite
A granite-like rock containing orthopyroxene, formed at high temperatures and pressures and often classed with the granulites.
igneous
White Tourmaline
A colorless to milky-white elbaite tourmaline known as achroite, the rare nearly pigment-free member of the tourmaline group.
gemstone
Hot Pink Tourmaline
An intensely saturated hot-pink to magenta elbaite tourmaline, among the most vivid and eye-catching of all pink rubellites.
gemstoneWatermelon Obsidian
A pink-and-green bicolor glass sold as obsidian; the watermelon coloring is manufactured and does not occur in natural volcanic glass.
igneous
Larvikite
A Norwegian intrusive rock whose feldspar crystals flash silvery-blue, widely used as blue pearl granite countertops.
igneous
Purple-Pink Tourmaline
Elbaite tourmaline in purplish-pink to magenta hues, colored by manganese, prized for its vivid orchid-like tones.
gemstone
Snowflake Obsidian
A black volcanic glass speckled with gray-white cristobalite snowflakes, formed as obsidian begins to crystallize.
igneousZebra Agate
A banded chalcedony agate with bold alternating dark and light stripes resembling zebra markings, sometimes color-enhanced.
gemstone
Cat's Eye Pink Tourmaline
Pink tourmaline cut en cabochon to reveal a moving band of light, a phenomenal gem colored by manganese with parallel inclusions.
gemstone
Zebra Jasper
A black-and-white striped chalcedony-quartz rock whose bold zebra-like banding makes it a popular ornamental and lapidary stone.
sedimentary
Albitite
A pale rock made almost entirely of the sodium feldspar albite, formed by sodic magmatism or sodium metasomatism.
igneous
Diorite
A coarse-grained intrusive rock with a distinctive salt-and-pepper look, the plutonic equivalent of andesite.
igneous
Graphic Feldspar
A pegmatite rock of feldspar intergrown with wedge-shaped quartz that resembles ancient runic or Hebrew writing.
igneous
Feldspathic Sandstone
A feldspar-rich sandstone, often pink, that points to granitic source rocks eroded quickly in dry or cold climates.
sedimentary