Formula: (Th,Pb,Ca)PO4.H2O Hexagonal
Description: Grayite is a rare member of the rhabdophane group found in rare element pegmatites.
DODGE COUNTY: Tiny grains of grayite-like mineral were seen in pegmatites cutting quartzite in the Michels Materials Waterloo Quarry, NE sec. 33 and NW sec. 34 T.9N. R.13E. (Buchholz et al. , 2003)
MARATHON COUNTY: Grayite has been documented as occurring in pegmatites in the Koss Pit, a large “rotten granite” quarry in the SW sec. 2 T.27N. R.5E. It is alos tentatively noted from the Maguire Pit in the Ladick Quarry complex (sec. 19 and 20 T. 27N. R.6E.) (Buchholz and Simons, 2002; Buchholz et al., 2004).