Granophyric Texture

A granophyric texture is an intergrowth of quartz and alkali feldspar in an igneous rock that is less well defined than a graphic texture and often is somewhat radiating. Granophyric texture can be similar to micrographic texture and to the coarser graphic intergrowths of quartz and alkali feldspar common in pegmatite.
These textures document simultaneous crystallization of quartz and feldspar from a silicate melt at the eutectic point, perhaps in the presence of a water-rich phase. They may also be formed by crystallization when the magma is significantly undercooled, not necessarily under eutectic conditions.

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
granitografico(2).jpg

Granophyre with graphic intergrowths of quartz and alkali feldspar. XPL image. 2x (Field of view = 7mm)
granitografico(3).jpg

Granophyre with graphic intergrowths of quartz and alkali feldspar. XPL image. 2x (Field of view = 7mm)
granitografico(4).jpg

Granophyre with graphic intergrowths of quartz and alkali feldspar. XPL image. 2x (Field of view = 7mm)
granitografico(5).jpg

Granophyre with graphic intergrowths of quartz and alkali feldspar. XPL image. 2x (Field of view = 7mm)
granitografico(6).jpg

Granophyre with graphic intergrowths of quartz and alkali feldspar. XPL image. 2x (Field of view = 7mm)
granitografico(7).jpg

Granophyre with graphic intergrowths of quartz and alkali feldspar. XPL image. 2x (Field of view = 7mm)
granitografico(8).jpg

Granophyre with graphic intergrowths of quartz and alkali feldspar. XPL image. 2x (Field of view = 7mm)
granitografico(10).jpg

Granophyre with graphic intergrowths of quartz and alkali feldspar. XPL image. 2x (Field of view = 7mm)
granitografico(11).jpg

Granophyre with graphic intergrowths of quartz and alkali feldspar. XPL image. 2x (Field of view = 7mm)
granitografico(12).jpg

Granophyre with graphic intergrowths of quartz and alkali feldspar. XPL image. 2x (Field of view = 7mm)
granitografico(13).jpg

Granophyre with graphic intergrowths of quartz and alkali feldspar. XPL image. 2x (Field of view = 7mm)
granitografico(14).jpg

Granophyre with graphic intergrowths of quartz and alkali feldspar. XPL image. 2x (Field of view = 7mm)