Mineral | Illite | K,H3O(Al,Mg,Fe)2(Si,Al)4O10[(OH)2·H2O] | Clay Mineral
Illite forms as a fine-grained clay mineral produced by the alteration of mica and feldspar. Occurs in shales and weathered sedimentary rocks.
Illite Displays These Colors
Green | Gray | Brown
Illite is Found in These Surrounding States
Ohio | Indiana | Kentucky | West Virginia | Pennsylvania | Michigan