(TL) indicates type locality. ? indicates mineral may be doubtful at this locality. All other localities listed without reference should be considered as uncertain and unproven until references can be found.
Sulphur Creek District (Sulfur Creek District; Wilbur Springs District)
Hanks, Henry Garber (1886), Sixth report of the State Mineralogist: California Mining Bureau. Report 6 part 1, 145 pp.: 125; Anderson, Charles A. (1936), Volcanic history of the Clear Lake area, California: Geological Society of America Bulletin: 47: 635; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 314.