Clinoatacamita ¿?
Clinoatacamita ¿? is a mineral with formula Cu₂(OH)₃Cl, in the Halogenuros group. This specimen comes from Mina Chuquicamata, Chuquicamata, Antofagasta, Chile.
Description
Not antlerite. Cavity lined with tiny, bright green, lustrous crystals forming a continuous drusy coating. Along the lower edge, a few sky-blue spheroidal aggregates, possibly chrysocolla; identification uncertain.
History of this specimen
Bought at the Vigo Mineral Show 2025 from Silvio J. Rodrigues, who was selling it as "antlerite". I said nothing because I acquired it together with piece 249, which was also mislabelled as galena with sphalerite and was in fact a huge calcite crest. Result: 2 out of 2 errors by the same seller, but two very interesting pieces.
About Clinoatacamita ¿?
Secondary formation in the oxidised zone of a large copper system. The first phase, probably clinoatacamite, crystallised over the cavity; later, on it or adjacent to it, spheroidal aggregates of another secondary mineral—possibly chrysocolla—were deposited, typical of supergene environments in arid climates such as Chuquicamata.
About the locality
Chuquicamata is a historic Chilean mine, noted for an oxidised zone rich in secondary copper minerals such as atacamite, brochantite, chrysocolla and clinoatacamite. It produces very good specimens.
Technical data
- Catalogue No.
- 0191
- Composition
- Cu₂(OH)₃Cl
- Name
- Clinoatacamita ¿?
- Group
- Halogenuros
- Category
- Cavella
- Associations
- Crisocola ¿?
- Mine
- Mina Chuquicamata
- District / Municipality
- Chuquicamata
- Province
- Antofagasta
- Country
- Chile
- Size (cm)
- 5 x 3.5 x 3
- Ex-collection
- Silvio J. Rodrigues
- Etymology
- From Greek "klino" ("inclination") and "atacamite", referring to its crystal habit distinct from that of atacamite.
- Quality
- Muy buena
- Value trend
- Estable
Related specimens
- Atacamita — Chile
- Brochantita — Chile
- Pachnolita — Dinamarca