Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Rutile
Rutile is a major titanium ore and the famous golden needle inclusion that gives rutilated quartz its shimmering threads.
mineral
Verdelite
The classic green gem variety of elbaite tourmaline, ranging from bright grass-green to deep forest tones colored by iron or chromium.
gemstoneMint Opal
A soft mint-green variety of common opal, usually opaque and colored by trace copper or nontronite inclusions rather than play-of-color.
gemstone
Chrysoberyl
An exceptionally hard beryllium aluminum oxide prized for golden hues, sharp cat's-eye effect, and the rare color-change alexandrite variety.
gemstone
Brecciated Jasper
A jasper made of angular fragments naturally cemented back together, typically showing red and brown pieces in a quartz matrix.
sedimentary
Blue Beryl
The blue color variety of beryl, ranging from pale sky tones to rich sea-blue, best known in its finest grades as aquamarine.
gemstone
Chrysocolla
A vivid blue-green hydrated copper silicate, soft on its own but prized as a gem when hardened by intergrown quartz or chalcedony.
mineralPink Obsidian
A pink to rose volcanic glass; some is natural iron-tinted obsidian while much sold commercially is color-treated glass.
igneous
Anthracite
The highest-rank coal, a hard, lustrous black rock that burns cleanly with little smoke and high heat output.
metamorphic
Pink Agate
A soft pink banded chalcedony, occurring naturally in delicate hues and also commonly produced by dyeing.
gemstone
Rhodonite
A rose-pink manganese silicate marbled with black veins, prized as a tough ornamental and occasionally faceted gemstone.
mineralLotus Garnet
A delicate pinkish-purple to peach garnet from Tanzania, a pyrope-spessartine blend named for the soft colors of a lotus flower.
gemstone
Raspberry Garnet
A vivid pinkish-red rhodolite garnet named for its raspberry color, a bright pyrope-almandine blend popular in jewelry.
gemstonePink Lady Obsidian
Obsidian showing a pink-to-rose sheen or hue; natural examples get color from interference effects, while uniform pink material is often manufactured glass.
igneous
Rhodolite Garnet
A purplish-red to raspberry garnet that is a natural blend of pyrope and almandine, prized for its bright rose-violet color.
gemstone
Pink Garnet
A trade name for pink garnets, mainly rhodolite, a rose-to-purplish pyrope-almandine blend prized for its bright clean color.
gemstone
Gypsum
A very soft sulfate mineral defining Mohs 2, occurring as selenite, satin spar, alabaster, and desert rose, used to make plaster.
mineralPink Opal
A soft pink common opal, most famously from Peru, valued for its gentle pastel color rather than play-of-color.
gemstone
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
Mozambique Garnet
An abundant, brightly colored pyrope-almandine garnet from East Africa, valued for its clean, raspberry-to-red gems at accessible prices.
gemstone
Rosterite
An old varietal name for alkali- and cesium-rich beryl, typically colorless to pale pink, overlapping with vorobyevite and morganite.
gemstone
Grossular Garnet
The calcium-aluminum garnet species spanning green tsavorite, cinnamon hessonite, and colorless leuco garnet — one of the most varied garnets.
gemstone