Mineral Specimen Images (A)

Arcanite: K2SO4

Comments: SEM image of a sub-spherical aggregate of arcanite.
Location: Ghar al Hibashi Harrat Nawasif/Al Buqum, Kingdom of Saudi Arabia. Scale: See Image.
© Saudi Geological Survey

Archerite: (K,NH4)H2PO4  
Biphosphammite: (NH4,K)H2PO4

Comments: Buff-colored biphosphammite with white archerite crusts.
Location: Cockelbiddy Cave, Western Australia, Australia. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Arctite: Na2Ca4(PO4)3F

Comments: Clear glassy crystalline arctite with magenta villiaumite in pegmatite.
Location: Vuonnemiok River, Khibiny Massif, Kola Peninsula, Murmansk District, Russia. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Ardaite: Pb19Sb13S35Cl7

Comments: B&W image of 1. Ardaite; 2. Chlorine-containing robinsonite; 3. Nadorite; 4. Anglesite; 5. Galena.
Location: Madjarovo polymetallic ore deposit, Bulgaria. (MinMag, v 46:340). Scale: Magnification 120 x.
© Mineralogical Magazine

Ardealite: Ca2(SO4)(HPO4)·4(H2O)

Comments: Ardealite powder.
Location: Moorba Cave, Jurien Bay, Western Australia, Australia. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Ardennite-(As): (Mn++,Ca,Mg)4(Al,Mg,Fe)6(SiO4)2(Si3O10)(AsO4,VO4)(OH)6

Comments: Yellow ardennite crystals in white quartz matrix.
Location: Salmchâteau, Vielsalm, Stavelot Massif, Ardennes, Luxembourg Province, Belgium. Scale: 30x20x17 mm.
© John Betts - Fine Minerals

Arfvedsonite: NaNa2(Fe++4Fe+++)Si8O22(OH)2

Comments: Prismatic crystals of black arfvedsonite in white feldspar matrix.
Location: Kangerdluarsuk, Ilímaussaq Massif, Greenland. Scale: 8x3x3 cm.
© John Betts - Fine Minerals

Arfvedsonite: NaNa2(Fe++4Fe+++)Si8O22(OH)2  
Seidozerite: (Na,Ca)2(Zr,Ti,Mn)2Si2O7(O,F)2

Comments: Dark red translucent seidozerite with vitreous, black arfvedsonite.
Location: Seidozero Lake, Lovozero Massif, Kola Peninsula, Murmansk District, Russia. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Argentite: Ag2S  
Acanthite: Ag2S

Comments: Dark metallic acanthite crystals up to 3 mm. Most of the crystals are a cubic habit, so the acanthite is pseudomorphing the original argentite.
Location: San Juan de Rayas Mine (Rayas Mine), Guanajuato, Mun. de Guanajuato, Guanajuato, Mexico. Scale: 18x12x12 mm.
© John Betts - Fine Minerals

Argentojarosite: AgFe+++3(SO4)2(OH)6

Comments: Yellow crystalline massive argentojarosite.
Location: Eagle Mine, Juab County, Utah, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Argentopentlandite: Ag(Fe,Ni)8S8  
Maucherite: Ni11As8

Comments: Reflected light image of a polished section containing argentopentlandite (AgP) with galena (G), native silver (Ag), chalcopyrite (Ch) and maucherite (M).
Location: Silver City, Ontonagon Co., Michigan, USA. Scale: Picture Size 900 µm.
© Jeff Weissman / Photographic Guide to Mineral Species

Argentopyrite: AgFe2S3

Comments: Metallic, twinned argentopyrite grain on matrix.
Location: St. Andreasberg, Harz, Lower Saxony, Germany. Scale: Size Not Given.
© Lou Perloff / Photo Atlas of Minerals

Argutite: GeO2

Comments: Sub microscopic grains of argutite invisible to the eye within sphalerite.
Location: Rimbatz, Argut-Dessus, Haute-Garonne, Midi-Pyrénées, France. Scale: Thumbnail 2.5 x 2 x 1.5 cm.
© Tom Loomis / Dakota Matrix

Argyrodite: Ag8GeS6

Comments: Lead gray metallic aggregate of argyrodite crystals.
Location: Veta Galufa, Colquechaca, Potosi Dept., Bolivia. Scale: Size Not Given.
© Lou Perloff / Photo Atlas of Minerals

Argyrodite: Ag8GeS6

Comments: Gray, metallic, massive, crystalline argyrodite ore.
Location: Himmelsfürst mine, Brand-Erbisdorf bei Freiberg, Erzgebirge, Sachsen. Scale: Picture size 4 mm.
© Thomas Witzke / Abraxas-Verlag

Arhbarite: Cu2Mg(AsO4)(OH)3

Comments: Deep blue, smooth, botryoidal aggregate of arhbarite in a 2mm vug associated with atacamite.
Location: El Guanaco mine, Atacama, Tal Tal(?), Chile. Scale: Picture size 1 cm.
© Tom Loomis / Dakota Matrix

Aristarainite: Na2MgB12O20·8(H2O)

Comments: B&W image of aristarainite crystals freed from the enclosing borax/kernite (AmMin, v59:647).
Location: Tincalayu mine, Salta, Argentina. Scale: See Image.
© American Mineralogist

Armalcolite: (Mg,Fe++)Ti2O5

Comments: Gray semi-metallic armalcolite micro crystals on coal.
Location: Chelyabinsk Oblast', Urals Region, Russia. Scale: See Image.
© Rruff Database

Armangite: Mn26As+++18O50(OH)4(CO3)

Comments: Black crystals of armangite on matrix.
Location: Langban, Varmland, Sweden.. Scale: Specimen Size 2.5 x 4 cm.
© John Veevaert

Armbrusterite: K5Na6Mn+++Mn++14[Si9O22]4(OH)10·4H2O

Comments: SEM image of a spherulite of platy crystals of armbrusterite (2 mm diameter) on cancrinite and calcite. (AmMin, v92:416).
Location: Khibiny massif, Kola Peninsula, Russia.. Scale: Spherulite Size 2 mm.
© American Mineralogist