metamorphosed diorite, with a fibrous amphibole component
epidiorite in American English
(ˌepɪˈdaiəˌrait)
noun
Geology
a schistose metamorphic rock resulting from the alteration of augite to hornblende in a gabbro or dolerite
Word origin
[1885–90; epi- + diorite]This word is first recorded in the period 1885–90. Other words that entered Englishat around the same time include: classified, foregut, seminar, toner, upsweepepi- is a prefix occurring in loanwords from Greek, where it meant “upon,” “on,” “over,”“near,” “at,” “before,” “after” (epicedium; epidermis; epigene; epitome). On this model, epi- is used in the formation of new compound words (epicardium; epinephrine)