Mineral Specimen Images (A)

Alarsite: AlAsO4

Comments: Small thread-like alarsite fragment held to sample peg by a drop of glue.
Location: Tolbachik Volcano, Main Fracture, North Breakthrough, Kamchatka Peninsula, Russia. Scale: Peg Size 2 mm.
© Diederik Visser

Albite: NaAlSi3O8  
Plagioclase: (Na,Ca)(Si,Al)4O8

Comments: Colorless, lustrous blocky albite crystals to 3 cm in size with a thick dusting of micaceous green micro chlorite.
Location: Acushnet Quarry, Bristol Co., Massachussetts, USA. Scale: 17 x 15 x 7.5 cm matrix.
© Dan Weinrich

Albite: NaAlSi3O8  
Plagioclase: (Na,Ca)(Si,Al)4O8

Comments: Crystal group of bladed albite (variety cleavelandite) crystals.
Location: Taquaral, Minas Gerais, Brazil. Scale: 7.4 x 5 cm.
© John Veevaert

Albite: NaAlSi3O8  
Schorl: NaFe++3Al6(BO3)3Si6O18(OH)4

Comments: Several jet-black lustrous crystals of schorl perched on a white albite matrix.
Location: Shengus, Gilgit, Pakistan. Scale: 4 x 3 x 2 cm.
© Isaias Casanova / IC Minerals

Aldermanite: Mg5Al12(PO4)8(OH)22·32(H2O)  
Minyulite: KAl2(PO4)2(OH,F)·4(H2O)

Comments: White, blocky aldermanite crystals to 2mm completely covering one face of matrix with colorless prismatic Minyulite crystals in sprays to 3mm.
Location: Tom's Phosphate quarry, Kapunda, South Australia, Australia. Scale: Overall: 2 x 1.5 x 2 cm.
© Tom Loomis / Dakota Matrix

Aleksite: PbBi2Te2S2 (?)

Comments: Gray, metallic aleskite grains in quartz with tellurobismuthite and Pb-bearing tetradymite.
Location: St. David's Mine, Bontddu, Dogellau, Gwynedd, Wales, UK. Scale: Specimen Size 2.5x4.5 cm.
© Diederik Visser

Alforsite: Ba5(PO4)3Cl

Comments: Three small grains of alforsite mounted on tape.
Location: La Madrelena, Baja California, Mexico. Scale: Not Given.
© Rhonda Spencer / ASDM Sonoran Desert Digital Library

Alforsite: Ba5(PO4)3Cl  
Titantaramellite: Ba4(Ti,Fe+++,Fe++,Mg)4(B2Si8O27)O2Clx X=0 TO 1, with Ti > Fe  
Sanbornite: BaSi2O5  
Celsian: BaAl2Si2O8

Comments: SEM image showing alforsite (al). Matrix composed by lamellar sanbornite (sa) and granular quartz (q). Rectangular crystal in the upper right corner is titantaramellite (ti) and isometric crystals included in sanbornite are celsian (ce).
Location: Trumbull Peak, near Incline, Mariposa Co., California, USA. Scale: See Image.
© Pavel M. Kartashov

Algodonite: Cu6As

Comments: Massive specimen of dark algodonite with vuggy areas filled with minute crystals.
Location: Algodones Mines, Coquímbo Province, Chile. Scale: 4x3x3 cm.
© John Betts - Fine Minerals

Algodonite: Cu6As  
Koutekite: Cu5As2

Comments: Silvery metallic koutekite with darker gray algodonite.
Location: Mohawk Mine, Keweenaw County, Michigan, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Aliettite: [Mg3Si4O10(OH)2](Ca0.5,Na)0.33(Al,Mg,Fe++)2-3(Si,Al)4O10(OH)2·n(H2O)

Comments: Tan to brownish pseudomorph of aliettite after wollastonite.
Location: Ingichka, Uzbekistan. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Allabogdanite: (Fe,Ni)2P  
Schreibersite: (Fe,Ni)3P

Comments: Relict grain of allabogdanite crystal (ABG) surrounded by schreibersite rim (SCHR) in plessite matrix (PL). Black phase is a secondary Fe-Ni-hydroxide. Backscattered electron image. (AmMin, 87:1249).
Location: Onello iron meteorite (high-Ni ataxite) Onello River basin, Aldan shield, Saha (Sakha) Republic (Yakutia), Eastern-Siberian Region, Russia. Scale: Scale bar 10 µ-m.
© American Mineralogist

Allactite: Mn7(AsO4)2(OH)8

Comments: Brownish red allactite crystals.
Location: Sterling Hill, Ogdensburg, Sussex County, New Jersey, USA. Scale: Size Not Given.
© Lou Perloff / Photo Atlas of Minerals

Allanite-(Ce): (Ce,Ca,Y)2(Al,Fe+++)3(SiO4)3(OH)

Comments: Dual views of the same 0.8 cm Jet black allanite-(Ce) on quartz.
Location: Tiro Estrella Mine, El Capitan Mts., Lincoln Co., New Mexico, USA. Scale: Crystal Size 0.8 cm.
© John Veevaert

Allanite-(La): Ca(REE,Ca)Al2(Fe++,Fe+++)(SiO4)(Si2O7)O(OH)

Comments: A single prismatic allanite-(La) crystal with small, lustrous black magnetite crystals, all on a matrix of hedenbergite.
Location: Mina Nueva Vizcaya, Sierra Gorda, Burguillos del Cerro, Badajoz, Spain. Scale: Crystal size 0.9 x 0.5 cm.
© Fabre Minerals

Allanite-(Y): (Y,Ce,Ca)2(Al,Fe+++)3(SiO4)3(OH)

Comments: Dark brown allanite-(Y) in matrix.
Location: Boden, Marienberg District, Erzgebirge, Saxony, Germany. Scale: Picture size 10 mm.
© Thomas Witzke / Abraxas-Verlag

Allanpringite: Fe3(PO4)2(OH)3·5H2O

Comments: Yellow crystals of allanpringite with cacoxenite and beraunite.
Location: Grube Mark, Essershausen, Weilburg, Taunus, Gerrmany. Scale: Picture size 1 cm.
© Diederik Visser

Allargentum: Ag1-xSbx(x=0.009-0.16)

Comments: Irregular crystalline aggregate grain of allargentum.
Location: Shaft 371, Schlema-Hartenstein area, Erzgebirge, Saxony, Germany. Scale: Specimen size 43 mm.
© Thomas Witzke / Abraxas-Verlag

Alleghanyite: Mn5(SiO4)2(OH)2

Comments: Massive, brown alleghanyite with white calcite.
Location: Parker Shaft, Franklin, Sussex County, New Jersey. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Alleghanyite: Mn5(SiO4)2(OH)2  
Galaxite: (Mn,Mg)(Al,Fe+++)2O4

Comments: Black granular galaxite with reddish alleghanyite and white kutnohorite.
Location: Bald Knob, Alleghany County, North Carolina, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species