Ref.: 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: 953.
Ream, Lanny R. (2004) Idaho Minerals, 2nd edition, Revised and Updated.
Slack (2006) Economic Geology: 101(2): 275-280.