Ref.: Rocks & Minerals: 12: 131-141.
Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II: 851.
Rocks & Minerals: 64: 471.
Rocks & Minerals: 70: 379.
American Mineralogist (1922): 7: 4-12.
Januzzi (1976), Mineral Localities of Connecticut and Southeastern New York State (Taylor Assoc./Mineralogical Press).
A feldspar and mica mine located on the West side of Collins Hill, 2½ miles (4 km) NE of Portland. Ore was a granite pegmatite hosted in Bolton schist. Started in 1904 by F.E. Strickland. Produced 2,000 to 5,000 long tons of feldspar per year and 200 to 400 tons of mica since 1927. Workings include an open cut 300 feet long by 200 feet wide and 140 feet deep. The quarry was closed when the ground water level was encountered. The quarry was filled in in recent years and is now under a golf course.
