Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Danburite
A glassy calcium borosilicate forming wedge-tipped prismatic crystals, usually colorless to pale yellow or pink, sometimes faceted as a gem.
crystal
Goshenite Crystal
The pure colorless variety of beryl, valued as crystal specimens and as a brilliant alternative to clearer gemstones.
crystal
Clear Obsidian
An unusually pure, transparent-to-translucent obsidian with few inclusions; truly water-clear specimens are rare in nature.
igneous
Goldstone
A man-made glittering glass packed with tiny copper crystals, traditionally reddish-brown but also made in blue and green.
crystal
Blue Goldstone
A man-made glittering glass colored deep blue with cobalt and studded with tiny copper crystals that mimic a starry night sky.
gemstone
Golden Healer Quartz
Quartz colored or coated by golden iron oxides such as limonite or goethite, giving a warm sunlit yellow glow.
crystalGold Sheen Obsidian
A black obsidian displaying a golden metallic sheen caused by light reflecting off aligned microscopic gas bubbles or mineral inclusions.
igneous
Golden Rainbow Obsidian
Black obsidian that displays a golden-to-rainbow iridescent sheen caused by aligned microscopic inclusions reflecting light.
igneous
Rhodonite
A rose-pink manganese silicate marbled with black veins, prized as a tough ornamental and occasionally faceted gemstone.
mineralGolden Peacock Obsidian
A natural sheen obsidian showing a warm gold shimmer plus peacock iridescence, caused by aligned nanoparticle layers within black glass.
igneous
Yellow Labradorite
A transparent yellow to golden gem variety of labradorite feldspar, usually faceted to show its clear, warm color.
gemstoneGraveyard Point Agate
A celebrated plume agate from the Oregon-Idaho border, known for dramatic black, gold, and red plumes in clear chalcedony.
gemstonePolyhedroid Agate
A rare agate that forms naturally with flat polygonal faces and angular geometric shapes rather than the usual rounded nodule.
gemstoneIce Opal
A clear, glassy, near-colorless opal resembling ice, sometimes with subtle internal flashes of play-of-color.
gemstone
Achroite
The rare colorless variety of tourmaline, named from the Greek for 'without color' and prized by collectors.
gemstone
Sunstone
A feldspar gemstone that sparkles with metallic glints (aventurescence) caused by tiny reflective copper or hematite platelets.
gemstone
Crystal Opal
Precious opal with a transparent or translucent body, letting play-of-color glow with exceptional depth and clarity.
gemstone
Rutilated Quartz
Clear or smoky quartz threaded with golden to reddish needles of rutile, also poetically called Venus hair stone.
crystal
Honey Agate
A warm golden to amber translucent chalcedony agate whose color and glow resemble honey, sometimes with banding.
gemstoneSunset Opal
An opal with warm sunset hues of orange, amber, and red, prized for its glowing fiery body color reminiscent of dusk skies.
gemstone
Bytownite
A calcium-rich plagioclase feldspar between labradorite and anorthite, faceted as transparent golden-yellow gems sometimes sold as yellow labradorite.
gemstone
Champagne Tourmaline
A soft brown to golden-brown tourmaline with warm, neutral tones reminiscent of sparkling champagne.
gemstone
Imperial Garnet
A trade name for high-brilliance golden grossular-andradite (grandite) garnet, most associated with the Mali deposits of West Africa.
gemstoneBronze Sheen Obsidian
Black volcanic glass with a warm bronze or coppery sheen produced by light reflecting off aligned microscopic inclusions.
igneous