Atacamita
Atacamita is a mineral with formula Cu₂Cl(OH)₃, in the Silicatos group. This specimen comes from Mina La Farola, Las Pintadas, Copiapó, Atacama, Chile and joined the Terrium collection in 1999.
Description
Flat sprays of atacamite: very dark green acicular and lamellar crystals with high lustre. The base is a white earthy crust of halloysite. There are also small dull green spherulitic aggregates of libethenite. Best examined with a hand lens.
History of this specimen
Comes with a Bottega delle Pietre (Milan) label. I note that the telephone number without prefix indicates the extraction/sale of the piece is earlier than December 1998.
About Atacamita
A basic copper chloride typical of oxidation zones in hyper-arid environments of northern Chile. The atacamite from Mina La Farola is exceptional in quality.
About the locality
La Farola ranks among the best localities worldwide for this species. It is a copper deposit in northern Chile known for supergene associations with acicular atacamite, libethenite, and alteration minerals on siliceous and granitic matrix.
Technical data
- Catalogue No.
- 0367
- Composition
- Cu₂Cl(OH)₃
- Name
- Atacamita
- Group
- Silicatos
- Category
- Meritum Persé
- Matrix
- Granítica
- Associations
- libethenita, halloysita
- Mine
- Mina La Farola
- District / Municipality
- Las Pintadas
- Province
- Copiapó
- Region
- Atacama
- Country
- Chile
- Size (cm)
- 6 x 5 x 1.5
- Weight
- 57 g
- Acquired
- 1999
- Etymology
- Discovered in 1801 and named after the Atacama Desert.
- Quality
- Muy buena
- Value trend
- Al alza
Related specimens
- Aerinita (fibrosa) — España
- Apofilita — India
- Asbesto —
- Boltwoodita — Namibia
- Boltwoodita — Estados Unidos
- Brochantita — Chile
- Clinoatacamita ¿? — Chile
- Coffinita — Estados Unidos