White Mountain Mica Co. (Thornton Hill) mine (Cameron eedow rroll Twin Mountain Base Sta Randolph o groN et al., 1954, p. 259). Grafton district pegmatite group (Cameron et al., Valencia mica mine Hackett mine Fletcher mine Craylip mica prospect Grafton district pegmatite group (Cameron et al., Olson, 1950, pl. 2). Charles Davis mica mine