There are 86 minerals that start with the letter O. From Oakite to Ozarkite. Minerals are naturally occurring, inorganic solids with a defined chemical composition and a crystalline structure. They are the building blocks of rocks and are classified based on their chemical properties, crystal structure, and texture. Minerals form through a variety of geological processes, including crystallization from molten rock, precipitation from solutions, and metamorphism under high pressure and temperature. They are essential not only for geological processes but also for many industrial applications and are critical for life, serving as nutrients in biological systems.
An intriguing fact about minerals is that some larval insects use mineral particles from the environment to enhance their camouflage, adapting to their surroundings for protection against predators. This innovative use of minerals demonstrates the complex interactions between organisms and their natural habitats.
Here’s what each of the columns in the table means:
Column Name: This column indicates the specific chemical elements or compounds that make up the mineral, defining its identity and properties.
Mohs hardness: This column provides a numerical scale from 1 to 10 that ranks the hardness of the mineral based on its ability to scratch or be scratched by other substances.
Common uses: This column outlines the various applications or industries where the mineral is utilized, highlighting its practical importance in everyday life and technology.
Description: This column includes a brief overview of the mineral’s appearance, characteristics, and unique features, providing essential information for identification and understanding its role in geology and industry.
Minerals That Start With O
| Minerals | chemical composition | Mohs hardness | common uses |
|---|---|---|---|
| Oakite | Ca(CO3) | 3-4(3.5) | flux in metallurgy |
| Obersteinite | (Mg,Fe)SiO3 | 5-6(5.5) | Decorative stone |
| Obsidian | SiO2 | 5-6(5.5) | Gemstone, tools |
| Occidentalite | Hydrous iron phosphate | 2.5-3.5(3.0) | Collector’s item |
| Oceanite | CaAl2Si2O8 | 6.0-7.0 | Gemstone, Mineral collection |
| Ochreous Opal | SiO2�nH2O | 5-6(5.5) | Gemstone |
| Ochrolite | (Cu,Zn)2+(V,Cr)6+O4 | 3.0-4.0 | Mineral collection |
| Octahedral Quartz | SiO2 | 7.0 | gemstones, abrasives |
| Octahedrite | TiO2 | 5.5-6(6.0) | Abrasive, pigment |
| Odinite | Hydrous iron silicate | 1.0-2.0(1.5) | None |
| Odintsovite | (Mg,Fe2+)2SiO4 | 6.5-7.0 | Mineral collection |
| Offretite | (K,Ca0.5,Na,Ba)6(Si,Al)12O24?7H2O | 4-5(4.5) | zeolite, absorbent |
| Oganesson | Og | n/a | research |
| Ogdensburgite | (Mn2+,Mg,Fe2+)2(VO4)2(OH) | 5.0-6.0 | Mineral collection |
| Oikocryst | Mineral with a unique ‘poikilitic’ texture, containing inclusions of other minerals | 6-7(6.5) | Geological analysis |
| Ojuela Adamite | Zn2(AsO4)(OH) | 3.5-4(3.5) | Collector’s item |
| Okanoganite-(Y) | (Y,REE,U,Th)(Ti,Nb,Fe)2O6 | 5.0-6.0(5.5) | Radioactive mineral |
| Okdaite | Mn2+Mn3+2O4 | 5.5-6.5(6.0) | pigment, ore |
| Okenite | Ca(Si2O4)(OH)2�H2O | 5-6(5.5) | Used in ceramics and glass |
| Oktaedrite | TiO2 | 5.5-6.0(5.5) | Jewelry, abrasives, pigments |
| Okunite | Ca(UO2)2(VO4)2�6-8H2O | 2.0-3.0 | Mineral collection |
| Olanzapine | C17H20N4S | N/A | Pharmaceutical |
| Olarlite | NiFe2O4 | 5.5-6.5(6.0) | magnetic materials |
| Oldenite | K(Al,Fe3+)2(Si3Al)O10(OH)2 | 2.0-3.0(2.5) | Ceramic raw material |
| Oldhamite | Calcium sulfide | 2.0-3.0(2.5) | None |
| Oledinite | KMg2(VO4)2(OH) | 4.5-5.0 | Mineral collection |
| Olekminskite | Na2U2O7�2-4H2O | 2.5-3.0 | Mineral collection |
| Olenshinskyite | (UO2)2(VO4)(OH) | 3.0-4.0 | Mineral collection |
| Olgite | Ni2SiO4 | 6.0-7.0(6.5) | ore, gemstone |
| Oligiste | Fe2O3 | 5.5-6.5(6.0) | Pigments, iron production |
| Oligoclase | (Na,Ca)(Si,Al)4O8 | 6-6.5(6.0) | Decorative stone |
| Oligoclase-Andesine | (Na,Ca)(Si,Al)4O8 | 6.0-6.5 | Building stone, Mineral collection |
| Oligonite | Iron carbonate | 3.5-4.0(3.8) | None |
| Olivenerz | (Fe2+,Mg)2SiO4 | 6.5-7.0 | Mineral collection |
| Olivenite | Cu2(AsO4)(OH) | 3.5-4(3.5) | Collector’s item |
| Olivine | (Mg,Fe)2SiO4 | 6.5-7(6.5) | Gemstone, industrial |
| Olivinite | Cu2+2(AsO4)(OH) | 3.5-4.0 | Mineral collection |
| Omani Amber | Organic compound | 2-2.5(2.0) | Gemstone, jewelry |
| Omeiite | CaMgSi2O6 | 5.5-6.0 | Mineral collection |
| Omphacite | (Ca,Na)(Mg,Fe,Al)(Si,Al)2O6 | 5.5-6.5(6.0) | gemstone |
| Oneillite | Calcium iron silicate hydroxide | 5.0-6.0(5.5) | None |
| Onofrite | Mercury antimony sulfide | 2.0-3.0(2.5) | None |
| Onufrievite | Ca2Fe3+4(PO4)4(OH)4 | 5-5.5(5.25) | Research, collector’s item |
| Onyx | SiO2 | 6-7(6.5) | Gemstone, decorative |
| Opal | SiO2�nH2O | 5-6(5.5) | Gemstone |
| Opalaite | Hydrous nickel silicate | 2.0-3.0(2.5) | None |
| Opalite | SiO2�nH2O | 5.5-6.5(6.0) | gemstone, ornamental |
| Ophir Gold | Au | 2.5-3.0(2.75) | jewelry, currency |
| Opie Copper | Cu | 2.5-3(2.5) | Collector’s item |
| Opocite | CuAl(AsO4)(OH)2 | 4.0-5.0(4.5) | ore, pigment |
| Oppenheimerite | (Fe,Ni)9S8 | 3.5-4.0 | Mineral collection |
| Orbitline | Ca2Mg5(VO4)4(OH)4 | 4-5(4.5) | Research, collector’s item |
| Ordonezite | Cu2+Fe3+O4 | 5.5-6.5(6.0) | ore, pigment |
| Ordovician Chert | Microcrystalline quartz | 7.0(7.0) | Gemstone, decorative stone |
| Oregonite | Na2Mg[B4O6(OH)4]�4H2O | 2.5-3.0 | Mineral collection |
| Orientite | Nickel iron silicate | 2.0-3.0(2.5) | None |
| Orikite | Ca3(UO2)2(VO4)2(OH)4�3-4H2O | 3-4(3.5) | Uranium ore, collector’s item |
| Orlandiite | CaV6+O3 | 5.0-5.5 | Mineral collection |
| Orlovite | Na2Mg[B4O6(OH)4]�4H2O | 2.5-3.0 | Mineral collection |
| Ornat | (Na,Ca)Al(SiO4)(OH,F) | 5-6(5.5) | Glass, ceramics, abrasives |
| Orogenic Quartz | Crystalline silica | 7.0(7.0) | Gemstone, decorative stone |
| Orpiment | As2S3 | 1.5-2(1.5) | Pigment, collector’s item |
| Orthamine | Manganese antimony oxide | 5.0-6.0(5.5) | None |
| Orthite | CaCe(Al,Fe)3(SiO4)3(OH) | 5.5-6.5(6.0) | gemstone |
| Orthobrannerite | (U,Th,Ca)2(Ti,Fe)2O6 | 5.0-6.0 | Mineral collection |
| Orthoclase | KAlSi3O8 | 6-6.5(6.0) | Decorative stone |
| Orthopinakiolite | Mg3(BO3)2 | 6.0-7.0 | Mineral collection |
| Orthorhombic Pyrite | FeS2 | 6.0-6.5(6.25) | ore, abrasive |
| Orthorhombic Quartz | SiO2 | 7.0 | gemstone, abrasive |
| Orthoxenobladeite | Ca2Mg[BO4]2 | 7.0-8.0 | Mineral collection |
| Osarizawaite | Lead copper sulfate hydroxide | 3.5-4.0(3.8) | None |
| Ostrowskite | (Fe,Ni)3O4 | 5.5-6.5(6.0) | ore, pigment |
| Osumilite | (K,Na)(Fe,Mg,Al)2(Al,Si)8O20 | 6-7(6.5) | Decorative stone |
| Otavite | CdCO3 | 4-4.5(4.0) | Collector’s item |
| Ottrelite | (Fe,Mg)2Al4Si2O10(OH)2 | 6-6.5(6.0) | Decorative stone |
| Otwayite | NiSiO3 | 5.5-6.5(6.0) | ore, gemstone |
| Oughtodite | (Fe3+,Fe2+,Mg)6(Si,Al)8O22(OH)2 | 5.5-6.5(6.0) | ore, abrasive |
| Owensite | Tungsten titanium oxide | 6.0-7.0(6.5) | None |
| Oxammite | Ammonium oxalate | 1.0-2.0(1.5) | None |
| Oxfordite | Calcium iron phosphate | 5.0-6.0(5.5) | None |
| Oxiphosporite | Ca(UO2)2(VO4)2�6-8H2O | 3.0-4.0(3.5) | ore, research |
| Oxyapatite | Calcium phosphate | 5.0-5.5(5.3) | None |
| Oxydravite | NaMg3Al6Si6O18(BO3)3(OH)3F | 6.0-7.0(6.5) | insulation, abrasive |
| Oxyhalite | Cu2(VO4)(OH) | 4.5-5.0 | Mineral collection |
| Oxythiohexahalite | Cu8(VO4)2(OH)6 | 4.0-4.5 | Mineral collection |
| Ozarkite | Ca(UO2)2(VO4)2�6-8H2O | 2.0-3.0 | Mineral collection |
Descriptions
Oakite
A calcium carbonate mineral that is used as a flux in metallurgical processes, particularly in the production of steel and other metals.
Obersteinite
A pyroxene mineral that typically forms dark green or black prismatic crystals. It is found in metamorphic and igneous rocks.
Obsidian
A naturally occurring volcanic glass formed as an extrusive igneous rock. It is known for its smooth, glassy appearance and has been used to create tools and decorative items.
Occidentalite
A rare phosphate mineral found in the western United States. It forms small blue-green or greenish-blue crystals or masses.
Oceanite
A rare calcium aluminum silicate mineral that forms white to pale green crystals. It is found in volcanic rocks and is sometimes used as a gemstone.
Ochreous Opal
A variety of opal that is yellow, brown, or reddish-brown in color due to the presence of iron oxides. It is often used in jewelry and decorative objects.
Ochrolite
A rare copper vanadate mineral that forms yellowish-green to olive-green crystalline masses or crusts. It is found in oxidized copper deposits.
Octahedral Quartz
A rare form of quartz that crystallizes in an octahedral shape, prized for its unique appearance and use in gemstones and as an abrasive material.
Octahedrite
A titanium oxide mineral that crystallizes in the tetragonal crystal system. It is used as an abrasive and in the production of white pigments.
Odinite
A rare, soft, green iron silicate mineral found in serpentinized ultramafic rocks.
Odintsovite
A rare magnesium iron silicate mineral that forms green to brown crystals. It is found in metamorphic rocks and is named after the Russian mineralogist V.I. Odintsov.
Offretite
A zeolite mineral that is used as an absorbent and in various industrial applications due to its porous structure and ion-exchange properties.
Oganesson
The 118th element on the periodic table, oganesson is a highly radioactive synthetic element with potential applications in nuclear research and technology.
Ogdensburgite
A rare manganese-bearing vanadate mineral that forms green to brown crystals. It is found in metamorphic and pegmatitic rocks.
Oikocryst
A type of mineral texture where a larger crystal encloses smaller crystals of other minerals, giving a ‘swiss cheese’ appearance.
Ojuela Adamite
A rare zinc arsenic hydroxide mineral that forms bright green to yellowish-green prismatic crystals. It is primarily of interest to mineral collectors.
Okanoganite-(Y)
A radioactive mineral that contains yttrium, rare earth elements, uranium, and thorium. It commonly forms in pegmatites and is used in the production of specialized ceramics.
Okdaite
A manganese oxide mineral that is used as a pigment and as an ore for the extraction of manganese.
Okenite
A hydrous calcium silicate mineral with a delicate, fibrous appearance. Often found in cavities and fractures of basaltic rocks.
Oktaedrite
A titanium dioxide mineral that is the rarer orthorhombic polymorph of anatase. It is used in similar applications as octahedrite, such as jewelry, abrasives, and pigments.
Okunite
A rare hydrous calcium uranyl vanadate mineral that forms yellow to greenish-yellow crystals. It is found in oxidized uranium deposits.
Olanzapine
A synthetic organic compound used as an antipsychotic medication. It is not a naturally occurring mineral.
Olarlite
A nickel-iron oxide mineral that has interesting magnetic properties and potential applications in the production of magnetic materials.
Oldenite
A mica group mineral that forms greenish-yellow to brown hexagonal plates. It is used as a ceramic raw material and in the production of refractory products.
Oldhamite
A rare, pale gray to brown, cubic calcium sulfide mineral found in some meteorites.
Oledinite
A rare potassium magnesium vanadate mineral that forms green to brownish-green crystals. It is found in metamorphic rocks.
Olekminskite
A rare hydrous sodium uranate mineral that forms yellow to yellowish-green crystals. It is found in oxidized uranium deposits.
Olenshinskyite
A rare hydrous uranyl vanadate mineral that forms yellow to greenish-yellow crystals. It is found in oxidized uranium deposits.
Olgite
A nickel-silicate mineral that is found as a secondary ore of nickel and can also be used as a gemstone.
Oligiste
An iron oxide mineral that is the main component of the mineral hematite. It is used as a pigment and in the production of iron and steel.
Oligoclase
A plagioclase feldspar mineral that forms white to gray, translucent crystals. It is commonly found in granitic and metamorphic rocks and is sometimes used as a decorative stone.
Oligoclase-Andesine
A plagioclase feldspar mineral that is an intermediate member of the albite-anorthite solid solution series. It forms white to gray crystals and is found in igneous and metamorphic rocks.
Oligonite
A rare iron carbonate mineral that forms rhombohedral crystals or granular masses.
Olivenerz
A rare iron-rich variety of the olivine group of minerals that forms dark green to black crystals. It is found in ultramafic igneous rocks.
Olivenite
A rare copper arsenic hydroxide mineral that forms bright green to yellowish-green prismatic crystals. It is primarily of interest to mineral collectors.
Olivine
A magnesium-iron silicate mineral that is a common constituent of mafic and ultramafic igneous rocks. It is used in the production of glass and ceramics and can also be used as a gemstone.
Olivinite
A rare copper arsenic oxide mineral that forms bright green to emerald-green crystals. It is found in copper-bearing ore deposits.
Omani Amber
A type of fossil resin found in Oman, used in the production of jewelry and decorative items. It is known for its distinctive golden-yellow color and organic chemical composition.
Omeiite
A rare calcium magnesium silicate mineral that forms white to pale green crystals. It is found in metamorphic rocks and is named after Mount Omei in China.
Omphacite
A pyroxene mineral that is valued for its unique appearance and use in gemstones.
Oneillite
A rare, green to brown calcium iron silicate hydroxide mineral found in metamorphic rocks.
Onofrite
A rare, yellowish-gray to brown mercury antimony sulfide mineral found in some mercury deposits.
Onufrievite
A rare calcium iron phosphate mineral discovered in Russia. It forms distinctive greenish-blue crystals and is of interest to researchers and collectors.
Onyx
A variety of chalcedony that features distinct bands or layers of different colors, typically black and white. It is a popular material for carving and used in jewelry, decorative objects, and architectural applications.
Opal
A hydrous silica mineral that is known for its unique and variable play of colors. It is a popular gemstone used in jewelry and is also found in various decorative and industrial applications.
Opalaite
A rare, green to blue-green hydrous nickel silicate mineral found in serpentinized ultramafic rocks.
Opalite
A variety of opal that is characterized by its milky, translucent appearance and is used in decorative and ornamental applications.
Ophir Gold
A natural gold mineral that is highly prized for its use in jewelry, currency, and other applications where the unique properties of gold are desired.
Opie Copper
A rare natural copper mineral that forms small, crystalline masses. It is primarily of interest to mineral collectors and is not commonly found in commercial applications.
Opocite
A copper-aluminum-arsenic mineral that is found as a secondary ore of copper and has also been used as a pigment.
Oppenheimerite
A rare iron-nickel sulfide mineral that forms silver-gray metallic crystals. It is found in iron-nickel meteorites and is named after the physicist J. Robert Oppenheimer.
Orbitline
A rare calcium magnesium vanadate mineral that forms distinctive circular patterns or ‘orbitlines’ on the surface of its crystals. It is primarily of scientific interest.
Ordonezite
A copper-iron oxide mineral that is found as a secondary ore of copper and has been used as a pigment.
Ordovician Chert
A type of chert found in Ordovician-aged rocks, often with distinctive banding or color patterns.
Oregonite
A rare hydrous sodium magnesium borate mineral that forms white to pale green crystals. It is found in evaporite deposits and is named after the U.S. state of Oregon.
Orientite
A rare, green to blue-green nickel iron silicate mineral found in serpentinized ultramafic rocks.
Orikite
A rare hydrous calcium uranium vanadate mineral with a bright yellow-green color. It is a valuable uranium ore and sought after by mineral collectors.
Orlandiite
A rare calcium vanadate mineral that forms yellow to orange-yellow crystals. It is found in oxidized vanadium deposits and is named after the Brazilian mineralogist Orlando da Luz.
Orlovite
A rare hydrous sodium magnesium borate mineral that forms white to pale green crystals. It is found in evaporite deposits and is named after the Russian mineralogist N.V. Orlov.
Ornat
A sodium-calcium aluminum silicate mineral that is used in the production of glass, ceramics, and as an abrasive material.
Orogenic Quartz
Quartz crystals formed during mountain-building (orogenic) processes, often with interesting color patterns or inclusions.
Orpiment
A rare sulfide mineral that forms bright yellow, crystalline masses. It has been used as a pigment and is also of interest to mineral collectors.
Orthamine
A rare, brown to black manganese antimony oxide mineral found in manganese deposits.
Orthite
A rare-earth-bearing silicate mineral that is valued for its use in gemstones and other decorative applications.
Orthobrannerite
A rare uranium-thorium titanium oxide mineral that forms black to dark brown crystals. It is found in pegmatites and is a member of the brannerite group.
Orthoclase
A potassium feldspar mineral that forms white to pink, translucent to opaque crystals. It is a common constituent of granitic and metamorphic rocks and is sometimes used as a decorative stone.
Orthopinakiolite
A rare magnesium borate mineral that forms white to colorless crystals. It is found in metamorphosed evaporite deposits.
Orthorhombic Pyrite
A rare polymorph of pyrite that crystallizes in an orthorhombic system and has potential uses as an ore of iron and as an abrasive material.
Orthorhombic Quartz
A rare polymorph of quartz that crystallizes in an orthorhombic system and is valued for its use in gemstones and as an abrasive material.
Orthoxenobladeite
A rare calcium magnesium borate mineral that forms white to pale green crystals. It is found in metamorphosed evaporite deposits.
Osarizawaite
A rare, blue to green lead copper sulfate hydroxide mineral found in oxidized copper deposits.
Ostrowskite
A nickel-iron oxide mineral that is found as a secondary ore of nickel and has been used as a pigment.
Osumilite
A rare magnesium-iron aluminosilicate mineral that forms hexagonal crystals. It is primarily of interest to mineral collectors and has limited use as a decorative stone.
Otavite
A rare cadmium carbonate mineral that forms yellow to greenish-yellow crystals. It is primarily of interest to mineral collectors and has no significant commercial applications.
Ottrelite
A rare iron-magnesium aluminum silicate mineral that forms dark green to black, platy crystals. It is sometimes used as a decorative stone but is not widely commercialized.
Otwayite
A nickel-silicate mineral that is found as a secondary ore of nickel and can also be used as a gemstone.
Oughtodite
An iron-magnesium silicate mineral that is found as a secondary ore of iron and has potential uses as an abrasive material.
Owensite
A rare, black tungsten titanium oxide mineral found in some metamorphic rocks.
Oxammite
A rare, colorless to white ammonium oxalate mineral found as a sublimation product in some caves.
Oxfordite
A rare, green to blue-green calcium iron phosphate mineral found in some iron deposits.
Oxiphosporite
A uranium-vanadium mineral that is found as a secondary ore of uranium and has potential applications in nuclear research and technology.
Oxyapatite
A rare, white to gray calcium phosphate mineral that is the oxygen-rich variety of apatite.
Oxydravite
A borosilicate mineral with a unique crystal structure that is used in the production of high-temperature insulation materials and as an abrasive.
Oxyhalite
A rare copper vanadate hydroxide mineral that forms bright green to emerald-green crystals. It is found in oxidized copper deposits.
Oxythiohexahalite
A rare copper vanadate hydroxide mineral that forms bright green to emerald-green crystals. It is found in oxidized copper deposits.
Ozarkite
A rare hydrous calcium uranyl vanadate mineral that forms yellow to greenish-yellow crystals. It is found in oxidized uranium deposits and is named after the Ozark region of the United States.
If you think there is a missing term, let us know using the contact form.