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
Ironstone
An iron-rich sedimentary rock, often heavy and rusty-weathering, historically mined as a major source of iron ore.
sedimentaryDragon Blood Jasper
A green-and-red ornamental stone of epidote and red piemontite or iron oxide, named for its dragon-skin coloring; not a true jasper.
metamorphic
Garden Quartz
Clear quartz filled with mineral inclusions that look like underwater gardens, mossy landscapes, or floating scenery.
crystal
Graphic Granite
A pegmatitic granite in which quartz and feldspar intergrow to resemble ancient runic or Hebrew script.
igneous
Rhodonite
A rose-pink manganese silicate marbled with black veins, prized as a tough ornamental and occasionally faceted gemstone.
mineral
Shattuckite
A rare deep-blue copper silicate mineral, often fibrous or massive, named for the Shattuck Mine in Arizona and prized by collectors.
mineral
Chrysocolla
A vivid blue-green hydrated copper silicate, soft on its own but prized as a gem when hardened by intergrown quartz or chalcedony.
mineralGary Green Jasper
An Oregon jasper, also called larsonite, of silicified fossil wood showing olive-green fields laced with black dendritic patterns.
mineral
Green Aventurine
A green quartz speckled with shimmering fuchsite mica that produces a glittering aventurescence, popular as an affordable ornamental stone.
mineral
Rutilated Quartz
Clear or smoky quartz threaded with golden to reddish needles of rutile, also poetically called Venus hair stone.
crystal
Amazonite
The blue-green gem variety of microcline feldspar, often mottled with white, prized as an affordable ornamental stone.
mineral
Microcline
A common potassium feldspar identical in composition to orthoclase but more ordered, famous for its green gem variety amazonite.
mineralAlabaster
A soft, fine-grained, translucent form of gypsum (or banded calcite) long prized as a carving and ornamental stone.
mineral
Garnet
A group of silicate gemstones best known for deep red but spanning nearly every color, including green tsavorite and orange spessartine.
gemstoneOnyx Marble
Translucent banded calcium-carbonate stone deposited in caves and springs, prized for ornamental carvings despite its softness.
sedimentaryFrost Agate
A pale chalcedony agate with cloudy, frost-like white patterning suggesting frost on a window or icy crystalline textures.
gemstone
Chevron Amethyst
A naturally banded quartz combining purple amethyst and white quartz in striking V-shaped chevron or zigzag patterns.
crystalImperial Jasper
A prized Mexican jasper known for pastel green, lavender, and cream orbicular patterns that take an exceptional polish.
mineral
Dendritic Opal
A common opal with branching, tree-like mineral inclusions that create natural fern, moss, or landscape patterns.
gemstone
Laguna Agate
A highly prized Mexican fortification agate from Chihuahua, famed for vivid red and orange banding with tight, intricate patterns.
gemstone
Bruneau Jasper
A prized Idaho picture jasper from Bruneau Canyon known for brown and cream orbicular egg-rock patterns and scenic landscapes.
mineralDouble Flow Obsidian
Obsidian formed from two merged lava flows, producing a stone with two distinct bands of sheen or color.
igneous
Hydrogrossular Garnet
A water-bearing massive grossular garnet, usually green or pink, widely used as a tough jade-like carving stone.
gemstone