Sagenitic Biotite

The term "sagenitic texture" refers to the occurrence of slender, needlelike inclusions intersecting at angles of 60° and included in phlogopite, quartz, or other minerals The most extensive study of sagenitic texture was carried out by NigSli (1965), who used electron microprobe techniquest o analyzes Sagenites in biotite from plutonic rocks. The genesis of inclusions of rutile is considered to be formed, in biotites and / or phlogopite rich in titanium, for exsolution phenomena, this gives rise to crystals of rutile and / or titanite.

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
Needlelike inclusions of rutile in Biotite. PPL image , 10x (Field of view = 2mm)	Needlelike inclusions of rutile in Biotite. PPL image , 10x (Field of view = 2mm)	Needlelike inclusions of rutile in Biotite. PPL image , 20x (Field of view = 1mm)
Needlelike inclusions of rutile in Biotite. PPL image , 10x (Field of view = 2mm)	Needlelike inclusions of rutile in Biotite. PPL image , 10x (Field of view = 2mm)	Needlelike inclusions of rutile in Biotite. PPL image , 10x (Field of view = 2mm)
Needlelike inclusions of rutile in Biotite. PPL image , 20x (Field of view = 1mm)	Needlelike inclusions of rutile in Biotite. PPL image , 20x (Field of view = 1mm)	Needlelike inclusions of rutile in Biotite. PPL image , 20x (Field of view = 1mm)