vitrophyre

rock

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Last updated

July 14, 2026

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Vitrophyre is a type of porphyritic glassy rock. It is formed from lava or magma with a chemical composition similar to granite. This molten material can cool to a glass without crystallizing, especially when it cools rapidly after extruding from a volcanic vent. Volcanic glass is unstable and tends to devitrify, meaning it changes from a glassy to a crystalline state over geologic time, often resulting in a stony appearance. Because of this, geologically ancient glassy rocks are rare.12

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igneous rock
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…rock can be called a vitrophyre. Other porphyritic rocks may well reflect less drastic shifts in position and perhaps more subtle and complex changes in conditions of temperature, pressure, or crystallization rates. Many phenocrysts could have developed at the points where they now occur, and some may represent systems with…
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…rock can be called a vitrophyre. Other porphyritic rocks may well reflect less drastic shifts in position and perhaps more subtle and complex changes in conditions of temperature, pressure, or crystallization rates. Many phenocrysts could have developed at the points where they now occur, and some may represent systems with…
Read More