Lazulite - (Mg,Fe2+)Al2(PO4)2(OH)2

Named in 1795 by Marten H. Klaproth from the term "Lazaward", which means heaven in Arabic, in allusion to its colour. Austria is the type locality of Lazulite, with the noteworthy localities of Fischbach, in Styria. In Italy, Lazulite comes from the Vizze pass, Bolzano Province; and from Monte Folgorito, Pietrasanta, Lucca Province. Lazulite is in a solid solution series with the mineral scorzalite. The lazulite-scorzalite series ranges from the magnesium rich lazulite to the iron rich scorzalite. The rarer scorzalite does not differ appreciably, except that it tends to be darker, less transparent and denser than lazulite.

It forms by high grade metamorphism of high silica quartz rich rocks and in pegmatites. It occurs in association with quartz, andalusite, rutile, kyanite, corundum, muscovite, pyrophyllite and dumortierite, in metamorphic terrains; and with albite, quartz, muscovite, tourmaline and beryl in pegmatites.
It may be confused with lazurite (a blue feldspathoid and a member of the sodalite group) or azurite (deep blue copper carbonate).

Optical Properties:

Habits: Dipyramidal crystal. Also granular and massive.
Color: Azure-blue, sky-blue, bluish white, yellow-green, blue-green, rarely green.
Pleochroism: Strong, from colorless to blue and darker blue.
Birefringence: High, II-III order.

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Deep-blue lazulite crystals, Horsjoberg, Varmland, Sweden. Immagine tratta da RRUFF.



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Deep-blue lazulite crystals, Champion mine, White Mountains, Mono County, California, USA. Immagine tratta da RRUFF.



Bibliography



• Cox et al. (1979): The Interpretation of Igneous Rocks, George Allen and Unwin, London.
• Howie, R. A., Zussman, J., & Deer, W. (1992). An introduction to the rock-forming minerals (p. 696). Longman.
• Le Maitre, R. W., Streckeisen, A., Zanettin, B., Le Bas, M. J., Bonin, B., Bateman, P., & Lameyre, J. (2002). Igneous rocks. A classification and glossary of terms, 2. Cambridge University Press.
• Middlemost, E. A. (1986). Magmas and magmatic rocks: an introduction to igneous petrology.
• Shelley, D. (1993). Igneous and metamorphic rocks under the microscope: classification, textures, microstructures and mineral preferred-orientations.
• Vernon, R. H. & Clarke, G. L. (2008): Principles of Metamorphic Petrology. Cambridge University Press.


Photo
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Lazulite (Azure-blue), siderite (brown) and quartz. Palermo mine pegmatite, New Hampshire (USA). PPL image, 1x (Field of view = 9mm)
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Lazulite (high birefringence), siderite and quartz. Palermo mine pegmatite, New Hampshire (USA). XPL image, 1x (Field of view = 9mm)
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Lazulite (Azure-blue), siderite (brown) and quartz. Palermo mine pegmatite, New Hampshire (USA). PPL image, 1x (Field of view = 9mm)
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Lazulite (high birefringence), siderite and quartz. Palermo mine pegmatite, New Hampshire (USA). XPL image, 1x (Field of view = 9mm)
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Lazulite (Azure-blue), siderite (brown) and quartz. Palermo mine pegmatite, New Hampshire (USA). PPL image, 1x (Field of view = 9mm)
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Lazulite (high birefringence), siderite and quartz. Palermo mine pegmatite, New Hampshire (USA). XPL image, 1x (Field of view = 9mm)
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Lazulite (Azure-blue), siderite (brown) and quartz. Palermo mine pegmatite, New Hampshire (USA). PPL image, 1x (Field of view = 9mm)
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Lazulite (Azure-blue), siderite (brown) and quartz. Palermo mine pegmatite, New Hampshire (USA). PPL image, 1x (Field of view = 9mm)
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Lazulite (high birefringence), siderite and quartz. Palermo mine pegmatite, New Hampshire (USA). XPL image, 1x (Field of view = 9mm)
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Lazulite (Azure-blue), siderite (brown) and quartz. Palermo mine pegmatite, New Hampshire (USA). PPL image, 1x (Field of view = 9mm)
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Lazulite (high birefringence), siderite and quartz. Palermo mine pegmatite, New Hampshire (USA). XPL image, 1x (Field of view = 9mm)
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Lazulite (Azure-blue), siderite (brown) and quartz. Palermo mine pegmatite, New Hampshire (USA). PPL image, 1x (Field of view = 9mm)
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Lazulite (Azure-blue), siderite (brown) and quartz. Palermo mine pegmatite, New Hampshire (USA). PPL image, 1x (Field of view = 9mm)
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Lazulite (high birefringence), siderite and quartz. Palermo mine pegmatite, New Hampshire (USA). XPL image, 1x (Field of view = 9mm)
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Lazulite (Azure-blue), siderite (brown) and quartz. Palermo mine pegmatite, New Hampshire (USA). PPL image, 1x (Field of view = 9mm)
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Lazulite (Azure-blue), siderite (brown) and quartz. Palermo mine pegmatite, New Hampshire (USA). PPL image, 1x (Field of view = 9mm)
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Lazulite (Azure-blue), siderite (brown) and quartz. Palermo mine pegmatite, New Hampshire (USA). PPL image, 1x (Field of view = 9mm)
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Lazulite (Azure-blue), siderite (brown) and quartz. Palermo mine pegmatite, New Hampshire (USA). PPL image, 1x (Field of view = 9mm)
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Cristalli di lazulite (alti colori di interferenza), siderite e quarzo in una pegmatite della miniera di Palermo, New Hampshire (USA). Immagine a NX, 1x (lato lungo = 9mm)
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Lazulite (Azure-blue), siderite (brown) and quartz. Palermo mine pegmatite, New Hampshire (USA). PPL image, 1x (Field of view = 9mm)
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Lazulite (Azure-blue), siderite (brown) and quartz. Palermo mine pegmatite, New Hampshire (USA). PPL image, 1x (Field of view = 9mm)
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Lazulite (Azure-blue), siderite (brown) and quartz. Palermo mine pegmatite, New Hampshire (USA). PPL image, 1x (Field of view = 9mm)
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Lazulite (high birefringence), siderite and quartz. Palermo mine pegmatite, New Hampshire (USA). XPL image, 1x (Field of view = 9mm)
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Lazulite (Azure-blue), siderite (brown) and quartz. Palermo mine pegmatite, New Hampshire (USA). PPL image, 1x (Field of view = 9mm)
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Lazulite (Azure-blue), siderite (brown) and quartz. Palermo mine pegmatite, New Hampshire (USA). PPL image, 2x (Field of view = 7mm)
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Lazulite (Azure-blue), siderite (brown) and quartz. Palermo mine pegmatite, New Hampshire (USA). PPL image, 2x (Field of view = 7mm)
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Lazulite (Azure-blue), siderite (brown) and quartz. Palermo mine pegmatite, New Hampshire (USA). PPL image, 2x (Field of view = 7mm)
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Lazulite (Azure-blue), siderite (brown) and quartz. Palermo mine pegmatite, New Hampshire (USA). PPL image, 2x (Field of view = 7mm)
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Lazulite (high birefringence), siderite and quartz. Palermo mine pegmatite, New Hampshire (USA). XPL image, 2x (Field of view = 7mm)
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Lazulite (Azure-blue), siderite (brown) and quartz. Palermo mine pegmatite, New Hampshire (USA). PPL image, 2x (Field of view = 7mm)
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Lazulite (Azure-blue). Palermo mine pegmatite, New Hampshire (USA). PPL image, 10x (Field of view = 2mm)
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Lazulite (high birefringence). Palermo mine pegmatite, New Hampshire (USA). XPL image, 10x (Field of view = 2mm)
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Lazulite (Azure-blue) and siderite (brown). Palermo mine pegmatite, New Hampshire (USA). PPL image, 10x (Field of view = 2mm)
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Lazulite (Azure-blue). Palermo mine pegmatite, New Hampshire (USA). PPL image, 10x (Field of view = 2mm)
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Lazulite (high birefringence). Palermo mine pegmatite, New Hampshire (USA). XPL image, 10x (Field of view = 2mm)
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Lazulite (Azure-blue) and siderite (brown). Palermo mine pegmatite, New Hampshire (USA). PPL image, 10x (Field of view = 2mm)
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Lazulite (Azure-blue). Palermo mine pegmatite, New Hampshire (USA). PPL image, 10x (Field of view = 2mm)
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Lazulite (high birefringence). Palermo mine pegmatite, New Hampshire (USA). XPL image, 10x (Field of view = 2mm)
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Lazulite (Azure-blue). Palermo mine pegmatite, New Hampshire (USA). PPL image, 10x (Field of view = 2mm)
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Lazulite (Azure-blue). Palermo mine pegmatite, New Hampshire (USA). PPL image, 10x (Field of view = 2mm)
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Lazulite (high birefringence). Palermo mine pegmatite, New Hampshire (USA). XPL image, 10x (Field of view = 2mm)
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Lazulite (Azure-blue). Palermo mine pegmatite, New Hampshire (USA). PPL image, 10x (Field of view = 2mm)
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Lazulite (Azure-blue). Palermo mine pegmatite, New Hampshire (USA). PPL image, 20x (Field of view = 1mm)
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Lazulite (Azure-blue). Palermo mine pegmatite, New Hampshire (USA). PPL image, 20x (Field of view = 1mm)
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Lazulite (high birefringence). Palermo mine pegmatite, New Hampshire (USA). XPL image, 20x (Field of view = 1mm)
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Lazulite (Azure-blue). Palermo mine pegmatite, New Hampshire (USA). PPL image, 20x (Field of view = 1mm)
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Lazulite (Azure-blue). Palermo mine pegmatite, New Hampshire (USA). PPL image, 20x (Field of view = 1mm)
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Lazulite (Azure-blue). Palermo mine pegmatite, New Hampshire (USA). PPL image, 20x (Field of view = 1mm)