In copper-bearing deposits, in areas with high chlorine concentrations or weathered while exposed to seawater; a reaction product of slag immersed in seawater.
IMA Status:
Valid Species (Pre-IMA) 1865
Locality:
In the Wheal Cock and West Wheal Owles, the Botallack and Levant mines, St. Just, and a few other places in Cornwall, England. Link to MinDat.org Location Data.
Name Origin:
For the occurrence in the Botallack mine, Cornwall, England.