Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Rose Quartz
The soft pink, usually cloudy variety of quartz colored by trace titanium or microscopic inclusions, popular for carvings and beads.
crystal
Banded Obsidian
Volcanic glass marked by parallel or swirling bands of differing color that record the flow layering of cooling lava.
igneousBronze Sheen Obsidian
Black volcanic glass with a warm bronze or coppery sheen produced by light reflecting off aligned microscopic inclusions.
igneous
Rainbow Obsidian
A black volcanic glass that reveals concentric rainbow bands of color when cut and polished against the light.
igneousVelvet Obsidian
A black volcanic glass with a soft, velvety internal sheen caused by aligned microscopic inclusions catching the light.
igneous
Pseudotachylite
A dark, glassy rock formed when frictional heat from fault movement or impact melts rock along narrow veins.
metamorphic
Brown Obsidian
Obsidian colored brown by iron oxide inclusions, frequently banded or swirled with black as in mahogany obsidian.
igneous
Snowflake Obsidian
A black volcanic glass speckled with gray-white cristobalite snowflakes, formed as obsidian begins to crystallize.
igneous
Hyalite Opal
A clear, glassy, botryoidal common opal famous for its intense green fluorescence under UV light, caused by trace uranium.
gemstoneMint Obsidian
A pale mint-green glass sold as obsidian; most uniform light-green material on the market is manufactured glass rather than natural volcanic obsidian.
igneous
Scepter Quartz
Quartz with a wider crystal 'cap' that grew over a narrower stem, forming a natural scepter or mushroom shape.
crystal
Water Opal
A transparent, colorless opal that looks like water or jelly, sometimes flashing subtle play-of-color from within.
gemstoneIridescent Obsidian
A black volcanic glass that displays shifting rainbow or metallic sheen from microscopic nanoparticle layers trapped inside.
igneous
Golden Healer Quartz
Quartz colored or coated by golden iron oxides such as limonite or goethite, giving a warm sunlit yellow glow.
crystalGreen Sheen Obsidian
Black volcanic glass that flashes a green sheen at certain angles due to light interference off aligned microscopic inclusions.
igneous
Tibetan Quartz
Clear quartz mined in the Himalayan region, often double-terminated and containing dark hematite or carbon inclusions.
crystal
Rainbow Velvet Obsidian
A natural sheen obsidian whose black glass displays a soft, velvety rainbow shimmer from aligned magnetite nanoparticles when polished and tilted.
igneous
Yellow Obsidian
Yellow to golden volcanic glass; natural examples owe their color to iron, though much bright yellow obsidian on the market is manufactured glass.
igneous
Lithium Quartz
A quartz crystal containing pink to lilac lithium-bearing mineral inclusions that give a soft cloudy lavender or rose coloration.
crystal
Jelly Opal
A translucent, gelatinous-looking opal whose transparency gives floating, glowing play-of-color a watery, jelly-like appearance.
gemstone
Aquamarine Matrix
Aquamarine crystals still attached to their natural host rock, prized as mineral specimens showing beryl in its original pocket setting.
mineral
Green Quartz
A green variety of macrocrystalline quartz, usually the heat- or radiation-altered prasiolite, prized for its soft mint hue.
crystalSilver Peacock Obsidian
A natural sheen obsidian combining a bright silver shimmer with iridescent peacock colors, all produced by nanoparticle layers in black glass.
igneous
Red Obsidian
Volcanic glass tinted red by fine iron-oxide inclusions, often blended with black to form mahogany-patterned obsidian.
crystal