Madupite

Madupite: Originally described as a melanocratic variety of leucitite essentially composed of diopside and phlogopite in a glassy matrix, which has the composition of nepheline and leucite. Wyomingite is a more felsic variety. Now regarded as a diopside madupitic lamproite. The name derives from the Shoshone Indian mad˙pa = Sweetwater. Wyoming, USA.

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Madupite outcrop. Pilot Butte volcanic center, Leucite Hills, Wyoming, USA. From James St. John.



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Madupite. Pilot Butte volcanic center, Leucite Hills, Wyoming, USA. From James St. John.




Bibliography



• Carmichael I.S.E., Turner F.J. & Verghoogen J. (1974): Igneous Petrology. McGraw-Hill. • Bergman, S. C.; 1987: Lamproites and other potassium-rich igneous rocks: a review of their occurrences, mineralogy and geochemistry. In: Alkaline Igneous rocks, Fitton, J.G. and Upton, B.G.J (Eds.), Geological Society of London.
• Mitchell, R. H.; Bergman, S. C. (1991). Petrology of Lamproites.
• Woolley, A.R., Bergman, S.C., Edgar, A.D, Le Bas, M.J., Mitchell, R.H., Rock, N.M.S. & Scott Smith, B.H., 1996. Classification of lamprophyres, lamproites, kimberlites, and the kalsilitic, melilitic, and leucitic rocks. The Canadian Mineralogist, Vol 34.


Photo
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Poikilitic phlogopite crystals, dioposide and Priderite (the small brown crystals in the groundmass) in a Madupite from Leucite hills. PPL image, 2x (Field of view = 7mm)
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Poikilitic phlogopite crystals and dioposide in a Madupite from Leucite hills. XPL image, 2x (Field of view = 7mm)
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Poikilitic phlogopite crystals, dioposide and Priderite (the small brown crystals in the groundmass) in a Madupite from Leucite hills. PPL image, 2x (Field of view = 7mm)
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Poikilitic phlogopite crystals and dioposide in a Madupite from Leucite hills. XPL image, 2x (Field of view = 7mm)
madupiteamerica(7).jpg

Poikilitic phlogopite crystal, dioposide and Priderite (the small brown crystals in the groundmass) in a Madupite from Leucite hills. PPL image, 10x (Field of view = 2mm)
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Poikilitic phlogopite crystal and dioposide in a Madupite from Leucite hills. XPL image, 10x (Field of view = 2mm)
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Poikilitic phlogopite crystal and dioposide in a Madupite from Leucite hills. XPL image, 2x (Field of view = 7mm)
madupiteamerica(10).jpg

Poikilitic phlogopite crystal, dioposide and Priderite (the small brown crystals in the groundmass) in a Madupite from Leucite hills. PPL image, 10x (Field of view = 2mm)
madupiteamerica(11).jpg

Poikilitic phlogopite crystals and dioposide in a Madupite from Leucite hills. XPL image, 2x (Field of view = 7mm)
madupiteamerica(12).jpg

Poikilitic phlogopite crystal, dioposide and Priderite (the small brown crystals in the groundmass) in a Madupite from Leucite hills. XPL image, 10x (Field of view = 2mm)
madupiteamerica(13).jpg

Poikilitic phlogopite crystal, dioposide and Priderite (the small brown crystals in the groundmass) in a Madupite from Leucite hills. XPL image, 10x (Field of view = 2mm)
madupiteamerica(14).jpg

Poikilitic phlogopite crystal, dioposide and Priderite (the small brown crystals in the groundmass) in a Madupite from Leucite hills. XPL image, 10x (Field of view = 2mm)