1) Plutonic rock
Found on
https://www.crosswordclues.com/clue/essexite
Essexite t, also called nepheline monzogabbro oʊ, is a dark gray or black holocrystalline plutonic igneous rock. Its name is derived from the type locality in Essex County, MA. Modern petrology identifies rocks according to mineralogical criteria. Utilising the IUGS QAPF diagram of Streckeisen (1974) `essexite` is more formally known as nepheli.....
Found on
http://en.wikipedia.org/wiki/Essexite
dark gray to black, fine-grained, intrusive igneous rock that occurs in Essex County, Mass.; at Mount Royal, near Montreal; near Oslo, Nor.; at ...
Found on
http://www.britannica.com/eb/a-z/e/46
No exact match found.
