Sentence Examples with the word Porphyrite

They comprise Seil, Easdale, Torsay, Luing and Shuna, and owe their name to the fact that they are composed mainly of metamorphic rocks, Easdale, Torsay and Luing being entirely slate, Seil mostly slate with some porphyrite in the north, and Shuna gneissose.

In China, at the close of the period, there were enormous eruptions of melaphyre, porphyrite and quartz-porphyry.