's Image Gallery

Nukundamite: (Cu,Fe)4S4  
Covellite: CuS

Comments: Metallic brownish rim of nukundamite with dark purplish-blue covellite on fine-grained pyrite.
Location: Ronneburg U deposit, Gera district, Thuringia, Germany. Scale: Picture size 7 mm.
© Thomas Witzke / Abraxas-Verlag

Nullaginite: Ni2(CO3)(OH)2

Comments: BSE image of a nullaginite nodule in a polished section. (CanMin, v19:315).
Location: Otwav deposit, Nullagine district, Western Australia.. Scale: See Image.
© Canadian Mineralogist

Nullaginite: Ni2(CO3)(OH)2

Comments: Green encrustations of nullaginite on matrix.
Location: Widgiemooltha, Western Australia, Australia. Scale: Sample size: 2 x 2 x 1 cm.
© Tom Loomis / Dakota Matrix

Numanoite: Ca4CuB4O6(OH)6(CO3)2  
Borcarite: Ca4MgB4O6(OH)6(CO3)2

Comments: Zoned borcarite (Bc) crystal with a core of green numanoite (Nm). CanMin 45:307.
Location: Fuka mine, 40 km west-northwest of Okayama City, western Japan. Scale: See Image.
© Canadian Mineralogist

Nyerereite: Na2Ca(CO3)2  
Gregoryite: (Na2,K2,Ca)CO3

Comments: Sodium (nyereteite) and potassium (gregoryite) carbonates, not stable in normal atmosphere, collected molten from the volcano and maintained in inert argon atmosphere.
Location: Ol Doinyo Lengai Vulkan, Maasai Steppe, East Africa Rift Valley, Tanzania. See Link. Scale: Rock size 2 cm.
© Richard Dale / Dale Minerals

Obertiite: NaNa2(Mg3Fe+++Ti)Si8O22(O,F,OH)2

Comments: Pinkish grains of obertiite in matrix.
Location: Bellerberg Mt., Eifel District, Rheinland-Phalz, Germany. Scale: Specimen Size 7x6 mm.
© Sergey Vasiliev / Systematic Mineralogy

Obradovicite: H4(K,Na)Cu++Fe+++2(AsO4)(MoO4)5·12(H2O)

Comments: Brownish yellow obradovicite coatings on quartz.
Location: Chuquicamata, Antofagasta, Chile. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Offretite: (K2,Ca,Mg)2.5Al5Si13O36·15(H2O)

Comments: Clear crystal of offretite on matrix.
Location: Mont Simiouse, near Montbrison, Loire, France. Scale: Not Given.
© Lou Perloff / Photo Atlas of Minerals

Ogdensburgite: Ca2(Zn,Mn)Fe+++4(AsO4)4(OH)6·6(H2O)

Comments: Reddish-brown, massive ogdensburgite.
Location: Ogdensburg, Franklin Mining District, Sussex Co., New Jersey, USA. Scale: Picture size 6 mm.
© Thomas Witzke / Abraxas-Verlag

Ohmilite: Sr3(Ti,Fe+++)(Si2O6)2(O,OH)·2-3(H2O)

Comments: Pale yellow translucent acicular ohmilite crystal cluster in matrix.
Location: Hashidate, Ohmi cho, Niigata, Japan. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Ojuelaite: ZnFe+++2(AsO4)2(OH)2·4(H2O)

Comments: Yellow-green ojuelaite masses on limonite and quartz.
Location: Mina Ojuela, Mapimi, Durango, Mexico. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Okanoganite-(Y): (Na,Ca)3(Y,Ce)12Si6B2O27F14

Comments: Cream-colored twinned crystal of okanoganite-(Y) on matrix.
Location: Washington Pass, Okanogan County, Washington, USA. Scale: Not Given.
© Lou Perloff / Photo Atlas of Minerals

Okayamalite: Ca2B2SiO7

Comments: Intergrowth between crystalline okayamalite (a) and amorphous silica (b). Okayamalite here forms regular lamellae elongated along [001], typically 400 Å thick. The grainy area (c) corresponds to the graphite film..
Location: Skarn sample from the Arendal district, Sorlandet, Norway. (AmMin, v85:1508). Scale: See Image.
© American Mineralogist

Okenite: Ca3[Si6O15]·6(H2O)

Comments: Cotton-ball cluster of white okenite crystals.
Location: Khandivali quarry, Maharashtra, India. Scale: 3x3x2 cm.
© John Betts - Fine Minerals

Oldhamite: (Ca,Mg,Fe)S

Comments: Brown crystalline oldhamite grains in anhydrite.
Location: Ronneburg, Thuringen, Germany. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Olenite: NaAl3Al6(BO3)3(Si6O18)(O,OH)4

Comments: Colorless, boron-rich crystal of Olenite in quartz.
Location: Koralpe, Styria, Austria. Scale: Crystal size 3 cm.
© Andreas Ertl / Institut für Mineralogie und Kristallographie

Olgite: Na(Sr,Ba)PO4

Comments: Green mm-sized olgite crystals in matrix.
Location: Kedykverpakhk Mt., Lovozero, Kola, Russia. Scale: Not Given.
© Sergey Vasiliev / Systematic Mineralogy

Oligoclase: (Na,Ca)(Si,Al)4O8  
Plagioclase: (Na,Ca)(Si,Al)4O8

Comments: Rectangular cleavage fragment of salmon-orange oligoclase (sunstone) feldspar.
Location: Norway. Scale: 47x30x7 mm.
© John Betts - Fine Minerals

Oligoclase: (Na,Ca)(Si,Al)4O8  
Plagioclase: (Na,Ca)(Si,Al)4O8

Comments: Clear glassy crystalline oligoclase with milky quartz and muscovite.
Location: Bakersville, Mitchell County, North Carolina, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Olivenite: Cu2AsO4(OH)

Comments: Dark green crystals of olivenite on matrix.
Location: Majuba Hill mine, Pershing County, Nevada, USA. Scale: Not Given.
© Lou Perloff / Photo Atlas of Minerals