's Image Gallery

Masutomilite: K(Li,Al,Mn++)3[(Si,Al)4O10](F,OH)2

Comments: Transparent to translucent micaceous pale violet masutomilite with yellow iron stains.
Location: Hisu Kawa Mine, Gifu, Japan. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Masuyite: Pb[(UO2)3O3(OH)2]·3(H2O)

Comments: Bright reddish orange crystals of masuyite.
Location: Shinkolobwe mine, Tantara, Shaba, Democratic Republic of the Congo. Scale: Not Given.
© Lou Perloff / Photo Atlas of Minerals

Masuyite: Pb[(UO2)3O3(OH)2]·3(H2O)

Comments: Dark reddish brown aggregate of masuyite with green metatorbernite on matrix.
Location: Musonoi mine, Kolwezi, Shaba, (Katanga), Congo (Zaïre). Scale: Picture size 2 mm.
© Paul M. Schumacher

Mathiasite: (K,Ca,Sr)(Ti,Cr,Fe,Mg)21O38

Comments: Mathiasite (M) exhibiting typical curvilinear cracks and incipient decomposition (upper left and lower right). Sample JFIS-I, Jagersfontein. Reflected light in air. (AmMin, v68:494).
Location: Metasomatized peridotites and heavy media concentrates from four kimberlites in the Republic of South Africa. Scale: Scale Bar 0.2 mm.
© American Mineralogist

Matildite: AgBiS2

Comments: Gray platy metallic crystalline matildite in white quartz.
Location: Sullivan Mountain, Montezuma District, Summit County, Colorado, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Matildite: AgBiS2  
Bismuth: Bi  
Bismuthinite: Bi2S3

Comments: SEM image of native Bi replaced by bismuthinite and matildite. Black areas represent gangue minerals. (CanMin, v43:899).
Location: Uranium deposit at Niederschlema-Alberoda, Germany. Scale: See Image.
© Canadian Mineralogist

Matioliite: NaMgAl5(PO4)4(OH)6·2H2O

Comments: fiberous, blueish, matioliite aggregate on quartz.
Location: Gentil mine, Mendes Pimentel, Minas Gerais, Brazil. Scale: See Image.
© American Mineralogist

Matlockite: PbFCl

Comments: Pale cream colored rosettes of matlockite crystals on matrix.
Location: Laurium, Greece. Scale: Not Given.
© Lou Perloff / Photo Atlas of Minerals

Matsubaraite: Sr4TiTi4Si4O22

Comments: Minute, dark grains of matsubaraite in a very pale green jadeite matrix.
Location: Itoigawa-Ohmi, Niigata Prefecture, Japan. Scale: Picture size 1 cm.
© American Mineralogist

Mattagamite: CoTe2  
Altaite: PbTe  
Tellurantimony: Sb2Te3

Comments: Silvery metallic intergrowths of mattagamite with tellurantimony and altaite.
Location: Mattagami Lake Mine, Quebec, Canada. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Mattheddleite: Pb20(SiO4)7(SO4)4Cl4

Comments: Radial aggregates of colorless hexagonal microcrystals of mattheddleite with minor blue-green caledonite.
Location: Dry Smale Gill, Roughton Gill, Caldbeck Fells, Cumbria (Cumberland), England, United Kingdom. Scale: See Image.
© Rruff Database

Matulaite: CaAl18(PO4)12(OH)20·28(H2O)

Comments: Opaque white pearly crystalline matulaite coating on quartz and brown limonite.
Location: Bachman Iron Mine, Hellertown, Northampton County, Pennsylvania, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Maucherite: Ni11As8

Comments: Massive, fine-grained, dark maucherite with cream-colored barite.
Location: Eisleben, Mansfeld Basin, Saxony-Anhalt, Germany. Scale: Specimen size 8 cm.
© Thomas Witzke / Abraxas-Verlag

Maucherite: Ni11As8

Comments: Reddish, semi-metallic aggregate of feathery maucherite crystals on matrix.
Location: Cobalt, Ontario, Canada. Scale: Picture size 2 mm.
© Reiner Mielke

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

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

Mawbyite: Pb(Fe+++Zn)2(AsO4)2(OH,H2O)2

Comments: Brown crystalline mawbyite in quartz.
Location: Kintore Open Cut, Broken Hill, New South Wales, Australia. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Mawsonite: Cu+6Fe+++2Sn++++S8

Comments: Mawsonite inclusions in brassy yellow chalcopyrite.
Location: Mount Lyell, Queenstown, Tasmania, Australia. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Mawsonite: Cu+6Fe+++2Sn++++S8

Comments: Polished Secton (PPL) showing traces of digenite (dig) throughout massive bornite (bn). A large grain of mawsonite (mw) is present at the bottom right.
Location: Kidd Creek Volcanogenic Massive Sulfide deposit, Western Abitibi Subprovince, Timmins, Ontario, Canada. Scale: Picture Size 0.5 mm.
© National Resouces of Canada

Maxwellite: NaFe+++(AsO4)F

Comments: Minute red translucent maxwellite crystal in rhyolite.
Location: Squaw Creek Tin Mine, Black Range, Catron County, New Mexico, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Mayenite: Ca12Al14O33

Comments: Gray mayenite grains in matrix.
Location: Bellerberg, Eifel, Germany. Scale: Picture size 1 mm.
© Diederik Visser