As a rare secondary mineral in the oxidized zone of lead-bearing base metal deposits.
IMA Status:
Valid Species (Pre-IMA) 1909
Locality:
From Mexico, in Sonora, at Alamos, and the San Pascual mine, Zimpan, Hidalgo. In the USA, from Arizona, in the Mammoth-St. Anthony mine, at Tiger, Pinal Co., the Lucky Cuss mine, Tomb
Link to MinDat.org Location Data.