See Also: greisen(medicine)
greisen(dictionary)

greisen (iou)



greisen noun. L19.
[German, prob. dial. from greis grey with age.]
Petrography. A light-coloured rock containing quartz, mica, and fluorine-rich minerals, produced by the pneumatolysis of granite.
greisening,
greiseni'zation nouns the pneumatolytic alteration of granite by fluorine-rich vapour E20.