Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Strawberry Quartz
A pink-to-red quartz colored by iron oxide inclusions that create a speckled, strawberry-like appearance within clear crystal.
crystal
Paintbrush Jasper
A scenic jasper whose flowing streaks of warm color resemble strokes left by a loaded paintbrush.
mineral
Bird's Eye Jasper
A microcrystalline quartz jasper marked by small concentric ring or eye patterns that resemble the eyes of birds.
mineral
Cave Creek Jasper
An opaque jasper from the Cave Creek area of Arizona, prized for earthy mottled and banded patterns in warm desert tones.
mineral
Willow Creek Jasper
A prized Idaho jasper known for porcelain-smooth pastel pinks, creams, and greens in soft swirling, orbicular patterns.
mineral
Ribbon Jasper
A banded jasper showing parallel ribbon-like stripes of contrasting color formed by layered silica and mineral deposition.
mineral
Flame Jasper
A fiery jasper whose red, orange, and yellow plumes lick across the stone like flames against an earthy background.
mineral
Cherry Creek Jasper
A landscape-patterned Chinese jasper prized for warm cherry-red, cream, and green bands resembling painted scenery.
mineral
Hydroandradite
A hydrous, iron-rich garnet of the hydrogarnet group in which hydroxyl groups substitute for silica within the andradite structure.
mineral
Metasandstone
Sandstone altered by metamorphism, with partly recrystallized quartz grains, transitional between true sandstone and quartzite.
metamorphic
Anorthosite
An intrusive igneous rock made almost entirely of plagioclase feldspar, famous as the rock of the lunar highlands.
igneous
Reptile Jasper
A green-and-black mottled jasper whose scale-like patterning resembles reptile skin, often linked to Kambaba and crocodile jaspers.
mineral
Butterstone Jasper
A soft-toned cream-to-butterscotch jasper colored by iron oxides, prized by lapidaries for its smooth, even, opaque finish.
gemstone
Stripe Obsidian
Obsidian crossed by parallel flow bands of differing color, formed as layers of lava with slightly different compositions froze into glass.
igneous
Snowflake Obsidian
A black volcanic glass speckled with gray-white cristobalite snowflakes, formed as obsidian begins to crystallize.
igneous
Porphyritic Obsidian
Natural volcanic glass speckled with embedded mineral crystals (phenocrysts) such as feldspar or cristobalite that grew before the lava chilled.
igneous
Purple Obsidian
Purple-colored volcanic glass; genuine natural purple obsidian is rare, with much purple obsidian being manufactured colored glass.
crystal
Metarhyolite
Rhyolite that has been metamorphosed, recrystallizing its silica-rich volcanic material into a tougher felsic metamorphic rock.
metamorphic
Fire Obsidian
A rare obsidian showing brilliant fiery iridescence caused by thin nanolayers of magnetite crystals diffracting light within the glass.
crystal
Blue Obsidian
Blue-colored volcanic glass; genuine natural blue obsidian is very rare, while much blue obsidian on the market is manufactured glass.
crystal
Forest Green Tourmaline
A deep, rich forest-green elbaite tourmaline (verdelite) colored mainly by iron, with strong pleochroism and excellent durability.
gemstone
Strawberry Garnet
A bright strawberry-red garnet, typically an almandine-pyrope blend prized for its juicy, lively red color in jewelry.
gemstone
Fire Agate
A rare brown chalcedony containing thin iron-oxide layers that produce flashing, fiery rainbow iridescence like trapped flames.
gemstone
Dragon 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