Vitrophyre

Example of a rhyolitic vitrophyre; large phenocrysts are set in the black glassy matrix

A vitrophyre is a porphyritic volcanic rock in which phenocrysts are embedded in a glassy matrix. Vitrophyres are contrasted from typical porphyritic rocks in that the latter has both crystalline phenocrysts (larger grains) and a crystalline matrix (smaller grains), whereas the former has a distinctly glassy matrix.[1] Vitrophyres can be alternatively described as rocks having vitrophyric texture.[2] This texture results from the rapid quenching of a lava where phenocrysts had started to form prior to eruption.[3]

  1. ^ Best, Myron G. (2002). Igneous and Metamorphic Petrology. Blackwell Publishing. p. 27. ISBN 9781405105880.
  2. ^ Winter, John D. (2014). Principles of Igneous and Metamorphic Petrology. Pearson. p. 40. ISBN 9781292021539.
  3. ^ Philpotts, Anthony; Ague, Jay (2009). Principles of Igneous and Metamorphic Petrology. Cambridge University Press. p. 198. ISBN 9780521880060.