Mineral Specimen Images (M)

Marecottite: Mg3(H2O)18[(UO2)4O3(SO4)2]2·10(H2O)

Comments: SEM image of a typical marecottite aggregate. Note the perfect cleavage along (011) and the trace of the twin composition plane (arrow). (AmMin, v 88, p 678).
Location: La Creusaz, Swiss Alps. Scale: See Image.
© American Mineralogist

Marecottite: Mg3(H2O)18[(UO2)4O3(SO4)2]2·10(H2O)  
Magnesiozippeite: Mg(H2O)3.5(UO2)2(SO4)O2

Comments: Powdery and crystalline aggregates of red-brown marecottite and yellow magnesiozippeite on matrix.
Location: Svornost Mine, Jachymov, Bohemia, Czech Republic. Scale: Specimen Size 6.5x9 cm.
© Diederik Visser

Margaritasite: (Cs,K,H3O)2(UO2)2V2O8·(H2O)

Comments: Bright yellow earthy margaritasite crust on rhyolite.
Location: Margaritas Open Pit Mine, Sierra Pena Blanca, Chihuahua,. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Margarite: CaAl2(Al2Si2)O10(OH)2

Comments: Beige, massive, fibrous/foliated aggregate of margarite crystals.
Location: Long Hill/Old Tungsten Mine in Trumbull, Connecticut, USA. Scale: 10 x 5 cm.
© Walter Mroch / Gem and Mineral Exploration Company

Margarosanite: Pb(Ca,Mn++)2Si3O9  
Minehillite: (K,Na)2-3Ca28(Zn4Al4Si40)O112(OH)16  
Wollastonite-1A: CaSiO3

Comments: White pearly crystalline minehillite with white margarosanite and dark gray lead, in pale pink opaque wollastonite (distinguished by blue-white fluorescence).
Location: Franklin, Sussex County, New Jersey, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Margarosanite: Pb(Ca,Mn++)2Si3O9

Comments: Clear or white, long, thin bladed crystals of margarosanite on matrix.
Location: Langban, Varmland, Sweden. Scale: Crystal size 1cm.
© Tom Loomis / Dakota Matrix

Marialite: Na4Al3Si9O24Cl

Comments: Fully terminated 4.3 cm crystal of marialite. Weakly fluorescent red under SW UV light.
Location: Gooderham, Haliburton Co., Ontario, Canada. Scale: 6 x 1.5 cm.
© John Veevaert

Marianoite: Na2Ca4(Nb,Zr)2(Si2O7)2(O,F)4

Comments: PPL image of euhedral crystals of marianoite, titanite and U-rich pyrochlore in the phlogopite-calcite silicocarbonatite. (CanMin, v46:1023).
Location: Mesoproterozoic Prairie Lake intrusive complex, in northwestern Ontario, Canada. Scale: See Image.
© Canadian Mineralogist

Marianoite: Na2Ca4(Nb,Zr)2(Si2O7)2(O,F)4

Comments: SEM images showing the morphology of marianoite crystals, (CanMin, v46:1023).
Location: Mesoproterozoic Prairie Lake intrusive complex, in northwestern Ontario, Canada. Scale: See Images.
© Canadian Mineralogist

Maricite: NaFe++PO4  
Vivianite: Fe++3(PO4)2·8(H2O)

Comments: Brown maricite nodule with internal radiating structure, with blue vivianite.
Location: Big Fish River, Yukon Territory, Canada. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Maricopaite: Pb7Ca2(Si,Al)48O100·32(H2O)

Comments: Opaque white prismatic maricopaite microcrystals and yellow crystalline mimetite.
Location: Moon Anchor Mine, near Tonopah, Maricopa County, Arizona, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Marinellite: [(Na,K)42Ca6](Si36Al36O144)(SO4)8Cl2·6(H2O)

Comments: Colorless to pale bluish-gray anhedral marinellite crystal.
Location: Monte Cavalluccio, Sacrofano, Campagnano di Roma, Italy. Scale: See Image.
© Rruff Database

Marokite: CaMn+++2O4

Comments: Dark brown crystalline massive marokite.
Location: vein #2, Tachgagalt, Ouarzazet, Morocco. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Marrite: PbAgAsS3

Comments: A prismatic crystal of marrite with small rounded crystals of galena in quartz.
Location: Lengenbach quarry, Binntal, Wallis (Valais), Switzerland. Scale: Picture size 1.3 mm.
© Thomas Witzke / Abraxas-Verlag

Marrite: PbAgAsS3  
Jordanite: Pb14(As,Sb)6S23

Comments: Aggregate of gray prismatic crystals of marrite on fine-grained jordanite.
Location: Lengenbach quarry, Binntal, Valais, Switzerland. Scale: Picture high 5 mm.
© Walter Gabriel

Marrucciite: Hg3Pb16Sb18S46

Comments: Black, acicular crystals of marrucciite embedded in dolomite marble..
Location: Buca della Vena Mine, Stazzema, Tuscany, Italy.. Scale: Picture size 4 mm.
© Thomas Witzke

Marshite: CuI

Comments: Translucent tetragonal crystal of marshite on matrix.
Location: Broken Hill, New South Wales, Australia. Scale: Not Given.
© Lou Perloff / Photo Atlas of Minerals

Marsturite: NaCaMn3[Si5O14(OH)]

Comments: Orange scaly marsturite on matrix.
Location: Molinello Mine, Val Graveglia, Genoa, Liguria, Italy. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Marthozite: Cu[(UO2)3(SeO3)2O2]·8(H2O)

Comments: Yellowish green coating of marthozite on matrix.
Location: Musonoi Mine, Katanga, Democratic Republic of the Congo. Scale: Not Given.
© John Veevaert

Marthozite: Cu[(UO2)3(SeO3)2O2]·8(H2O)

Comments: Olive green crystal of marthozite showing multiple face development on main crystal. Schumacher Collection.
Location: Musonoi Mine, Kolwezi, Western area, Shaba Cu belt, Shaba (Katanga), Congo (Zaïre). Scale: Picture size 5 mm.
© Paul M. Schumacher