Holohyaline texture
A term applied to igneous rocks that have a glassy texture. Holohyaline rocks were generally cooled rapidly, which inhibits growth rate and nucleation of crystals. A few tiny crystals, called microlites, may be present.
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
![osssidiana(14).jpg](/immagini/vulc/piccole/osssidiana(14).jpg)
Obsidian with magmatic foliation. PPL image , 2x (Field of view = 7mm) |
![osssidiana(3).jpg](/immagini/vulc/piccole/osssidiana(3).jpg)
Volcanic glass showing perlitic texture (concentric curved fractures) in a Holohyaline rock. PPL image , 10x (Field of view = 2mm) |
![osssidiana(4).jpg](/immagini/vulc/piccole/osssidiana(4).jpg)
Volcanic glass showing perlitic texture (concentric curved fractures) in a Holohyaline rock. PPL image , 10x (Field of view = 2mm) |
![osssidiana(5).jpg](/immagini/vulc/piccole/osssidiana(5).jpg)
Volcanic glass showing perlitic texture (concentric curved fractures) in a Holohyaline rock. PPL image , 10x (Field of view = 2mm) |
![osssidiana(6).jpg](/immagini/vulc/piccole/osssidiana(6).jpg)
Volcanic glass showing perlitic texture (concentric curved fractures) in a Holohyaline rock. PPL image , 10x (Field of view = 2mm) |
![osssidiana(7).jpg](/immagini/vulc/piccole/osssidiana(7).jpg)
Volcanic glass showing perlitic texture (concentric curved fractures) in a Holohyaline rock. PPL image , 10x (Field of view = 2mm) |
![osssidiana(8).jpg](/immagini/vulc/piccole/osssidiana(8).jpg)
Obsidian with magmatic foliation. PPL image , 2x (Field of view = 7mm) |
![osssidiana(9).jpg](/immagini/vulc/piccole/osssidiana(9).jpg)
Obsidian with magmatic foliation. PPL image , 2x (Field of view = 7mm) |
![osssidiana(10).jpg](/immagini/vulc/piccole/osssidiana(10).jpg)
Obsidian with magmatic foliation. XPL image , 2x (Field of view = 7mm) |
![osssidiana(11).jpg](/immagini/vulc/piccole/osssidiana(11).jpg)
Obsidian with magmatic foliation. PPL image , 10x (Field of view = 2mm) |
![osssidiana(12).jpg](/immagini/vulc/piccole/osssidiana(12).jpg)
Obsidian with magmatic foliation. PPL image , 10x (Field of view = 2mm) |
![osssidiana(13).jpg](/immagini/vulc/piccole/osssidiana(13).jpg)
Obsidian with magmatic foliation. XPL image , 10x (Field of view = 2mm) |
![osssidiana(18).jpg](/immagini/vulc/piccole/osssidiana(18).jpg)
Crystallites in a Obsidian. PPL image , 10x (Field of view = 1mm) |
![osssidiana(15).jpg](/immagini/vulc/piccole/osssidiana(15).jpg)
Crystallites in a Obsidian. PPL image , 10x (Field of view = 1mm) |
![osssidiana(16).jpg](/immagini/vulc/piccole/osssidiana(16).jpg)
Crystallites in a Obsidian. PPL image , 10x (Field of view = 1mm) |
![osssidiana(17).jpg](/immagini/vulc/piccole/osssidiana(17).jpg)
Crystallites in a Obsidian. PPL image , 10x (Field of view = 1mm) |