Mineral Specimen Images (A)

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  
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

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  
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

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

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  
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

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

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

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

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

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

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

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