Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Lavender Tourmaline
A delicate pale purple elbaite tourmaline in soft lavender and lilac tones, colored by manganese.
gemstoneAurora Obsidian
A trade name for rainbow-sheen obsidian whose aligned nanoparticles produce shifting aurora-like bands of color.
igneous
Lavender Opal
A pastel purple variety of common opal, valued for its gentle lilac body color rather than any play-of-color.
gemstone
Grape Agate
Clusters of tiny botryoidal chalcedony spheres resembling bunches of grapes, famously purple, found in Indonesia.
mineralIridescent Obsidian
A black volcanic glass that displays shifting rainbow or metallic sheen from microscopic nanoparticle layers trapped inside.
igneous
Fire Obsidian
A rare obsidian showing brilliant fiery iridescence caused by thin nanolayers of magnetite crystals diffracting light within the glass.
crystal
Labradorite
A plagioclase feldspar famous for labradorescence, a dramatic flash of iridescent blue, green, and gold across a dark gray stone.
mineral
Lepidolite
A soft lithium-bearing mica with a lilac to purple color and pearly, flaky sheen, an important ore of lithium.
mineral
Banded Obsidian
Volcanic glass marked by parallel or swirling bands of differing color that record the flow layering of cooling lava.
igneous
Siberite
A historic name for the red-violet to purplish lithium tourmaline first prized from Siberia, closely tied to the rubellite variety.
gemstone
Charoite
A rare swirling lilac-to-violet silicate found only in Siberia, prized for its fibrous, chatoyant purple patterns.
mineral
Sugilite
A rare deep-purple manganese-bearing silicate, mostly from South Africa, prized for its vivid violet color.
mineral
Rhodolite Garnet
A purplish-red to raspberry garnet that is a natural blend of pyrope and almandine, prized for its bright rose-violet color.
gemstone
Ametrine
A natural bicolor quartz that combines purple amethyst and golden citrine in a single crystal.
crystalLotus Garnet
A delicate pinkish-purple to peach garnet from Tanzania, a pyrope-spessartine blend named for the soft colors of a lotus flower.
gemstoneAutumn Jasper
A warm-toned jasper named for its autumn-leaf palette of browns, rust, gold, and cream, popular as soothing earth-tone beads.
mineralFlame Obsidian
Black volcanic glass that flashes flame-like bands of iridescent color when light strikes aligned nanoscale inclusions.
igneous
Fire Agate
A rare brown chalcedony containing thin iron-oxide layers that produce flashing, fiery rainbow iridescence like trapped flames.
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.
gemstone
Peacock Opal
A precious opal showing dominant peacock-like blue, green and teal play-of-color, often on Ethiopian material.
gemstone
Bornite
A copper iron sulfide famous for its vivid iridescent purple-blue tarnish, the classic peacock ore and a copper ore.
mineral
Star Opal
Opal that displays a radiating, star-shaped pattern of play-of-color, a rare and prized internal structure.
gemstone
White Moonstone
The classic moonstone: a milky-white feldspar showing the prized floating blue-to-silver adularescent glow that gives the gem its name.
gemstoneCosmic Obsidian
A trade name for sheen obsidian whose swirling, patchy iridescence resembles galaxies and nebulae against deep black glass.
igneous