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



• Deer, W.A., Howie, R.A., Zussman, J. (1998) Rock-forming Minerals.
• Optical Mineralogy : The Nonopaque Minerals by Phillips / Griffen
• E. WM. Heinrich (1956): Microscopic Petrografy. Mcgraw-hill book company,inc
• Cox et al. (1979): The Interpretation of Igneous Rocks, George Allen and Unwin, London.

Photo
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Obsidian with magmatic foliation. PPL image , 2x (Field of view = 7mm)
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Volcanic glass showing perlitic texture (concentric curved fractures) in a Holohyaline rock. PPL image , 10x (Field of view = 2mm)
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Volcanic glass showing perlitic texture (concentric curved fractures) in a Holohyaline rock. PPL image , 10x (Field of view = 2mm)
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

Volcanic glass showing perlitic texture (concentric curved fractures) in a Holohyaline rock. PPL image , 10x (Field of view = 2mm)
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

Obsidian with magmatic foliation. PPL image , 2x (Field of view = 7mm)
osssidiana(9).jpg

Obsidian with magmatic foliation. PPL image , 2x (Field of view = 7mm)
osssidiana(10).jpg

Obsidian with magmatic foliation. XPL image , 2x (Field of view = 7mm)
osssidiana(11).jpg

Obsidian with magmatic foliation. PPL image , 10x (Field of view = 2mm)
osssidiana(12).jpg

Obsidian with magmatic foliation. PPL image , 10x (Field of view = 2mm)
osssidiana(13).jpg

Obsidian with magmatic foliation. XPL image , 10x (Field of view = 2mm)
osssidiana(18).jpg

Crystallites in a Obsidian. PPL image , 10x (Field of view = 1mm)
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Crystallites in a Obsidian. PPL image , 10x (Field of view = 1mm)
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Crystallites in a Obsidian. PPL image , 10x (Field of view = 1mm)
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Crystallites in a Obsidian. PPL image , 10x (Field of view = 1mm)