A vitrophyre is a

porphyritic Porphyritic is an adjective used in geology to describe igneous rocks with a distinct difference in the size of mineral crystals, with the larger crystals known as phenocrysts. Both extrusive and intrusive rocks can be porphyritic, meaning ...

volcanic rock Volcanic rocks (often shortened to volcanics in scientific contexts) are rocks formed from lava erupted from a volcano. Like all rock types, the concept of volcanic rock is artificial, and in nature volcanic rocks grade into hypabyssal and me ...

in which

phenocrysts 300px, Swiss side of the Mont Blanc massif, has large white phenocrysts of plagioclase (that have trapezoid shapes when cut through). 1 euro coin (diameter 2.3 cm) for scale. A phenocryst is an early forming, relatively large and usually conspic ...

are embedded in a glassy

matrix Matrix (: matrices or matrixes) or MATRIX may refer to: Science and mathematics * Matrix (mathematics), a rectangular array of numbers, symbols or expressions * Matrix (logic), part of a formula in prenex normal form * Matrix (biology), the m ...

. 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. Vitrophyres can be alternatively described as rocks having vitrophyric texture. This texture results from the rapid quenching of a lava where phenocrysts had started to form prior to eruption.

References

{{reflist, 1 Volcanic rocks

See also

References