A vitrophyre is a porphyriticvolcanic rock in which phenocrysts are embedded in a glassymatrix. 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]