Is it possible to have a fine-grained diorite?

Andesite is the extrusive version of this intermediate igneous rock, and Diorite the intrusive, meaning that Diorite is the rock that cools slowly underground. So the answer to your question would depend on what you mean by fine. If you're going by the strict definition, the fine-grained rock would be Andesite. read more

Yes, I have seen diorite in dikes, like the one above along I-64 out of Richmond Va on the way up and over the Blue Ridge. It is olive green and as fine grained as a limestone. read more

Quora Andesite is the extrusive version of this intermediate igneous rock, and Diorite the intrusive, meaning that Diorite is the rock that cools slowly underground. read more