Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Orange Calcite
A soft, glowing orange variety of calcite colored by iron oxides, popular as tumbled stones and known for fizzing in acid.
mineral
Calcite
An extremely common calcium carbonate mineral that comes in nearly every color and shows strong double refraction in clear crystals.
mineral
Orange Tourmaline
A warm orange to tangerine tourmaline, an uncommon hue produced by manganese and iron in the crystal.
gemstone
Blue Calcite
A soft, soothing powder-blue variety of calcite, a common calcium carbonate mineral often sold as gentle tumbled stones.
mineral
Honey Calcite
A warm golden-to-amber variety of calcite, a soft calcium carbonate mineral valued for its honeyed glow and easy carving.
mineral
Green Calcite
A soft mint-to-apple-green variety of calcite, a common calcium carbonate mineral popular as soothing tumbled stones.
mineral
Orange Opal
A vivid orange opal, classically Mexican fire opal, prized for its bright, fiery body color that glows when backlit.
gemstone
Orange Obsidian
Obsidian colored orange by iron oxide inclusions; vivid uniform orange material is frequently manufactured glass rather than volcanic.
igneous
Orange Garnet
A trade term for orange garnets, mainly manganese-rich spessartine and the brownish hessonite variety of grossular.
gemstone
Iceland Spar
A transparent, optical-grade variety of calcite famous for strong double refraction, splitting images and light into two rays.
mineral
Sparite
Coarse, clear-to-white crystalline calcite that cements limestones, contrasting with fine muddy micrite.
sedimentary
Chevron Amethyst
A naturally banded quartz combining purple amethyst and white quartz in striking V-shaped chevron or zigzag patterns.
crystal
Aquamarine Matrix
Aquamarine crystals still attached to their natural host rock, prized as mineral specimens showing beryl in its original pocket setting.
mineral
Tangerine Obsidian
A vivid orange glass sold as obsidian; uniformly bright tangerine material is typically manufactured glass rather than natural volcanic obsidian.
igneous
Emerald in Matrix
Natural emerald crystals still embedded in their host rock, prized as mineral specimens that show how the gem grew in place.
gemstone
Calcrete
Carbonate-cemented soil crust formed in arid regions where calcium carbonate accumulates and hardens within the regolith.
sedimentary
Caliche
A hardened soil crust cemented by calcium carbonate, forming a tough whitish layer common in arid and semi-arid regions.
sedimentary
Onyx Marble
Translucent banded calcium-carbonate stone deposited in caves and springs, prized for ornamental carvings despite its softness.
sedimentary
Aragonite
A calcium carbonate mineral and polymorph of calcite, aragonite forms distinctive needle clusters, sea shells, and pearls.
mineral
Desert Rose
A rosette-shaped cluster of bladed gypsum or barite crystals that traps sand, forming flower-like formations in arid deserts.
mineral
Tangerine Tourmaline
A vivid tangerine-orange elbaite tourmaline colored by manganese, offering a bright, citrusy hue that is uncommon in tourmaline.
gemstone
Wulfenite
A lead molybdate mineral famous for thin, brilliant orange to yellow tabular crystals, prized by collectors and an ore of molybdenum.
mineral
Apricot Tourmaline
A warm apricot to peachy orange-pink elbaite tourmaline colored mainly by manganese, prized for its soft, glowing warmth.
gemstone
Sunset Tourmaline
A warm-hued tourmaline blending orange, pink and red tones reminiscent of a sunset sky.
gemstone