Mineralpedia Details for Botallackite
Named for the Botallack mine where the mineral finds its type locality in Wheal Cock in the St. Just district of Cornwall, England. Additional localities for Botallackite include additional English localites, Scotland, Ireland, Germany, Greece, South Africa, the United States, and long the Mid-Atlantic Ridge in the TAG Hydrothermal Field, among a few others. It can be found in copper-bearing deposits with high chlorine concentrations or have been exposed to seawater, as a reaction product of slag in seawater, and a weathering product of sulfides in black smoker deposits. Botallackite is found in association with atacamite, paratacamite, gypsum, brochantite, and connellite.
Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/botallackite.pdf
Botallackite from Botallack mine, St. Just dist., Cornwall, England
Originally described in 1865 and generally thought to be Atacamite, Botallackite (monoclinic) is actually polymorphous with Atacamite(Ortho). These crystals to about 0.5mm are composed of stacked, thin plates, much like an uneven and fanned deck of cards.
Botallackite from Levant mine, St. Just dist., Cornwall, England
Pearly light green flat lying bladed Botallackite crystals to 5mm long.