Wikipedia contributors. (2023, October 19). Mineral. In Wikipedia, The Free Encyclopedia. Retrieved October 29, 2023, from https://en.wikipedia.org/w/index.php?title=Mineral&oldid=1180818427
Bald Hill, northwest of Monroe, consists primarily of andesite flows. These blue-green porphyritic rocks weather quite readily to a light grey material with a reddish hue which can easily be disintegrated by hand. At several localities on Bald Hill vertical dikes are exposed which contain andesite xenoliths in a fine grained matrix.
Mineral (Wikipedia) In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.