Acari Mine, Acarí District, Caravelí Province, Arequipa, Peru
Acari copper district, near Nazca is the source of Andean Opals, dendritic opals and Pink opals, which were most likely formed originally in a volcanic lake environment. Opals occur within a few km of the copper mining area. The opal there forms veins up to 5 cm thick.The area has been producing Pink Opal for at least 35 years. It is usually pale pink there, but thin veins of dark red-pink were found around 1995. The amount of polygorskite in Pink Opal is about 40%.
Ref: J.Hyrsl (2012) Gemstones of Peru, pp. 61, 62