American Mineralogist's Image Gallery

Abelsonite: Ni++C31H32N4

Comments: Abelsonite (A) grain associated with authigenitc orthoclase (O) and a micaceous mineral (M). (AmMin, v63:930).
Location: Wosco sample (Sec 36 T9S R20E) (Depth 2508.2 - 2508.15). Drill cores in or near the Mahogany Zone oil shale of the Green River Formation in Uintah County, Utah, USA. Scale: Magnification 800 X.
© American Mineralogist

Abswurmbachite: Cu++Mn+++6SiO12

Comments: Series of images showing the out-crop, the selected nodule and finally a BSE image of abswurmbachite. (AmMin, v86:205).
Location: Sanbagawa metamorphic belt, Japan. Scale: See Images.
© American Mineralogist

Aegirine-augite: (Ca,Na)(Mg,Fe++,Fe+++)[Si2O6]  
Dellaventuraite: NaNa2(Mg2,Mn+++,Li,Ti)Si8O22O2

Comments: View in plane-polarized light of reddish brown dellaventuraite (OPTK) as an overgrowth on purple-gray aegirine-augite (AE-AG) in a matrix of rounded quartz (QZ) with minor rounded (high relief) apatite grains. (AmMin 90:306).
Location: Kajlidongri manganese mine, Jhabua District, Madhya Pradesh, India. Scale: Picture size 2.5 cm.
© American Mineralogist

Akimotoite: (Mg,Fe)SiO3

Comments: Electron micrograph of akimotoite (Ak) as columnar grains. Aggregates of akimotoite are adjacent to a large clinoenstatite grain (Cen) with (100) twin lamallae. (AmMin 84:268).
Location: Shock-metamorphosed Tenham chondrite. Scale: See Image.
© American Mineralogist

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

Alpersite: (Mg,Cu)SO4·7H2O

Comments: Bright blue efforescence associated with pickeringite, alunogen, and epsomite. Pickeringite and alunogen (white and yellow) occur on top of a matte of alpersite (blue) adjacent to a concrete wall.
Location: Big Mike mine, Nevada. Scale: Picture size 50 cm.
© American Mineralogist

Aluminocerite-(Ce): (Ce,REE,Ca)9(Al,Fe+++)(SiO4)3[SiO3(OH)]4(OH)3

Comments: BSE image of the holotype of aluminocerite-(Ce) showing pseudo-octahedral to rombohedral crystals flattened on the c axis. (AmMin v94:488).
Location: Ratti quarry near Baveno, Italy.. Scale: See Image.
© American Mineralogist

Aluminum: Al

Comments: Deep-green phlogopite with Al flake (at the center). AmMin, 94:1983.
Location: Found in a desilicated pegmatite vein, NW Rila Mountain, Bulgaria. Scale: Scale Bar 1 mm.
© American Mineralogist

Andreyivanovite: FeCrP

Comments: BSE image of serpentine (gray) grain containing curvilinear arrays of andreyivanovite crystals (A) and associated florenskyite (F) lath. AmMin v93, p1296.
Location: Kaidun meteorite (South Yemen). Scale: Scale Bar 20 µm.
© American Mineralogist

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

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

Aspidolite: NaMg3AlSi3O10(OH)2

Comments: B&W thin section (PPL) of a clinopyroxene leuconorite showing Na-rich phlogopite surrounding corroded plagioclase (Pl). (AmMin, v86:29).
Location: Gabbroic crustal zenoliths form Volcan San Pedro, Chilean Andes. Scale: See Image.
© American Mineralogist

Balkanite: Cu9Ag5HgS8

Comments: B&W image of a polished section of balkanite with polysynthetic twinning. (AmMin v58:11).
Location: Sedmochislenitsi mine, Vratsa district, in the western part of the Stara Planina, Bulgaria. Scale: 330 X.
© American Mineralogist

Bamfordite: Fe+++Mo2O6(OH)3·(H2O)

Comments: Scanning electron micrograph showing the typical morphology of bamfordite crystals. (AmMin, 83:173).
Location: Abandoned W-Mo-Bi mines at Bamford, Queensland, Australia. Scale: Scale Bar 20 µm.
© American Mineralogist

Barioperovskite: BaTiO3

Comments: BSE image showing one area where barioperovskite (BaTiO3) micro- to nano-crystals occur in the tubular inclusion, along with BaTi2O5 and fresnoite. Inset B&W image shows inclusion in benitoite with area of magnification in red outline.
Location: Benitoite Mine, San Benito County, California, U.S.A. Scale: See Images.
© American Mineralogist

Barringtonite: MgCO3·2(H2O)  
Lansfordite: MgCO3·5(H2O)

Comments: Optical images of clusters of glassy lansfordite crystals and one white dehydrated barringtonite ? crystal. (AmMin, 88:1883).
Location: Crystals associated with the remains of a saguaro, Carnegiea gigantea from south and west central Arizona. Scale: Scale bar 800 µ-m.
© American Mineralogist

Bartonite: K3Fe10S14

Comments: B&W polished section image showing an irregular remnant of bright pyrrhotite (py) in a matrix of bartonite (ba) veined by silicates. (AmMin, v66:369).
Location: Found in a mafic, alkalic diatreme at Coyote Peak, Humboldt County, California, USA. Scale: Picture Size 1.3? x 1.94 mm.
© American Mineralogist

Baumstarkite: Ag3(Sb,As)2SbS6

Comments: Fragments of baumstarkite with zoning of darker lamellae with higher As content. (AmMin 87:755).
Location: San Genaro mine, Huancavelica Department, Peru.. Scale: See Image.
© American Mineralogist

Bernalite: Fe(OH)3

Comments: B&W image of pseudo-octahedral crystals of bernalite on goethite. (AmMin, v78:827).
Location: Proprietary mine, Broken Hill, New South Wales, Australia. Scale: Scale Bar 3 mm.
© American Mineralogist

Birchite: Cd2Cu2(PO4)2(SO4)·5H2O

Comments: SEM image showing bladed crystals of birchite on anglesite. The crystals are flattened on (100) and show the principal forms {100}, {010}, and {101}. (AmMin, v93:912).
Location: Block 14 Opencut, Broken Hill, New South Wales, Australia. Scale: Scale Bar 50µm.
© American Mineralogist