Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Autumn Jasper
A warm-toned jasper named for its autumn-leaf palette of browns, rust, gold, and cream, popular as soothing earth-tone beads.
mineralMaligano Jasper
A rare Indonesian jasper from Sulawesi known for ghostly tube structures, brecciated patterns, and contrasting grey, red, and purple zones.
mineralFlame Jasper
A fiery jasper whose red, orange, and yellow plumes lick across the stone like flames against an earthy background.
mineral
Brown Jasper
An opaque earth-toned jasper colored brown by iron oxides, ranging from pale tan to deep chocolate.
mineral
Jaspillite
A banded, metamorphosed iron formation in which bright red jasper alternates with silvery hematite or magnetite layers.
metamorphic
Banded Iron Formation
Ancient chemically deposited rock of alternating iron-oxide and silica bands recording Earth's early oxygenation and a major iron ore source.
sedimentary
Red Obsidian
Volcanic glass tinted red by fine iron-oxide inclusions, often blended with black to form mahogany-patterned obsidian.
crystalReptile Jasper
A green-and-black mottled jasper whose scale-like patterning resembles reptile skin, often linked to Kambaba and crocodile jaspers.
mineral
Bog Iron
A soft, porous iron ore of limonite and goethite that forms in wetlands and bogs, historically the first iron source for many cultures.
sedimentary
Gahnite
A hard zinc-rich member of the spinel group, usually dark blue-green to black, forming octahedral crystals in metamorphic and pegmatitic rocks.
mineral
Chrysoberyl
An exceptionally hard beryllium aluminum oxide prized for golden hues, sharp cat's-eye effect, and the rare color-change alexandrite variety.
gemstone
Spinel
A durable magnesium aluminum oxide gem that occurs in many colors and was long mistaken for ruby.
gemstone
Brecciated Jasper
A jasper made of angular fragments naturally cemented back together, typically showing red and brown pieces in a quartz matrix.
sedimentary
Mandarin Garnet
The intensely glowing orange variety of spessartine garnet, prized for its pure 'Fanta-orange' fire and high brilliance.
gemstone
Columbite
A black iron-manganese niobate that is a primary ore of niobium, forming a continuous series with tantalite (together called coltan).
mineral
Tantalite
A dense black iron-manganese tantalate that is the chief ore of tantalum, forming a series with columbite and mined as coltan.
mineral
Ironstone
An iron-rich sedimentary rock, often heavy and rusty-weathering, historically mined as a major source of iron ore.
sedimentary
Golden Healer Quartz
Quartz colored or coated by golden iron oxides such as limonite or goethite, giving a warm sunlit yellow glow.
crystal
Yttrium Aluminum Garnet
A synthetic garnet-structured oxide (YAG) used as a diamond simulant and laser crystal, with no natural counterpart.
gemstone
Cave Creek Jasper
An opaque jasper from the Cave Creek area of Arizona, prized for earthy mottled and banded patterns in warm desert tones.
mineralUmbalite Garnet
A delicate pink to lavender garnet from Tanzania's Umba Valley, a pyrope-spessartine blend often marketed as a soft, light-toned rhodolite.
gemstone
Bauxite
An earthy aluminum-rich residual rock and the world's principal ore of aluminum, often showing distinctive pea-like pisolites.
sedimentaryLotus Garnet
A delicate pinkish-purple to peach garnet from Tanzania, a pyrope-spessartine blend named for the soft colors of a lotus flower.
gemstonePaintbrush Jasper
A scenic jasper whose flowing streaks of warm color resemble strokes left by a loaded paintbrush.
mineral