Atacamite is the first of these biominerals known to contain copper [Science, 298, 389 (2002)].
The hardness and stiffness of the jaw increases from the base to the tip and from the surface to the interior, which correlates with the increasing degree of mineralization.
This toughness is needed to protect the jaw from wear and tear as the worm burrows through gritty marine sediment where it may chomp indiscriminately on bits of gravel.
Atacamite (a copper hydroxychloride) crystals on chrysocolla from the type locality of the La Farola Mine, Copiapó, Chile.There's also malachite and rosasite on the goethite/limonite matrix.
The rarest of the atacamite polymorphs, this miniature of bright green botallackite (a copper hydroxychloride) on matrix was collected in the mid-1990s from the Dooneen Mine, Allihies, Beara Peninsula, County Cork, Ireland.
It's a polymorph with atacamite, clinoatacamite, and paratacamite.
Its hardness is about 3 and B specific gravity 3~ 7, while its tolour presents various shades of een, usually dark.
Atacamite is a comparatively rare mineral, (I rmed in some cases by the action of sea-water on various a1 pper-ores, and occurring also as a volcanic product on Vesuvian h van.
Atacamite, in pulverulent state, was formerly used as a pounce under the me of Peruvian green sand, and was known in Chile as ;enillo.
Atacamite is an unusual and attractive halide mineral.
Atacamite forms in arid climates where copper minerals are exposed to oxidation.
Atacamite has a deep green color and is often associated with many other rare and colorful minerals such as chyrsocolla, brochantite, pseudomalachite, connellite, linarite, caledonite, libethenite, cornetite, cuprite and malachite.
Among the incrustations he was able to identify the ruby-red protoxide of copper (cuprous oxide: cuprite); the green rust of the carbonate (basic copper carbonate: malachite) and submuriate of copper (basic copper chloride: probably paratacamite or atacamite); crystals of metallic copper that had been redeposited; and a dirty white material identified as tin oxide.
The presence of paratacamite or atacamite on the surface of a bronze object does not necessarily mean that the object is undergoing active corrosion.
Bronze disease: Synthesis and characterisation of botallackite, paratacamite and atacamite by infra-red spectroscopy.
CHLORINE ISOTOPE AND BROMINE EVIDENCE OF A JURASSIC SEDIMENTARY CHLORIDE SOURCE FOR ATACAMITE MINERALIZATION AT THE ...(Site not responding. Last check: 2007-11-01)
Supergene mineralization at the Radomiro Tomic porphyry copper deposit involves the copper-chloride mineralatacamite, distributed in a thick oxide zone as the main ore mineral.
In contrast, elevated bromine content, (22 to 180 ppm) and d37Cl values near 0.0 for the atacamitemineralization at Radomiro Tomic are clearly indicative of a non-magmatic origin for the mineralizing chloride.
Nearby Jurassic sediments appear to be the source of chloride in the atacamitemineralization at the Radomiro Tomic deposit, with the later influence of marine evaporites on exotic copper deposited in the overlying gravel.
Atacamite, a copper chloride hydroxide mineral, was found by the writer on one specimen in the Harvard Mineralogical Museum and was verified solely by X-ray diffraction.
It occurs as bright green microscopic crystals associated with radial, prismatic ganophyllite, rhodonite, and marsturite.
Atacamite is exceedingly rare at Franklin and has not been reported from Sterling Hill.
The Introduction of Chloride into the Radomiro Tomic Porphyry Copper Deposit, Chile(Site not responding. Last check: 2007-11-01)
Along with it's previous scarcity, knowledge of the properties of atacamite and behavior of atacamite in porphyry systems is not well constrained or understood.
We have proposed four reaction processes which generate atacamite in porphyry copper systems from the oxidation of hypogene chalcocite in the presence of: 1)biotite, 2) orthoclase, 3) sericite, and 4) a complete granitic system, in a chemical system open to aqueous chloride.
With a better understanding of the factors controlling the formation of atacamite, future deposits of the low sulfur and hence environmentally friendly ore could be found by targeting geochemically or hydrologically favorable regions.
This exceptional specimen comes from the OTHER famous locality for well-crystallized old Aussie atacamites, as opposed to the elongated slender crystals from Moonta and Kadina in the Yorke Peninsula which are perhaps more famous in the old books and museum collections.
These atacamites, forming lustrous, tabular crystals to 1.5 cm, are exceptional in quality.
The crystals show two generation of growth, with the upper part of the specimen having the second generation of smaller, darker platy crystals on two “knobs” that are accented by the lighter-colored crystals on the bottom of the specimen.
Gem, Rock, and Mineral Postage Stamps Featuring Atacamite(Site not responding. Last check: 2007-11-01)
Nomenclature: Named after the Atacam desert province in northern Chile.
Additional Notes: Atacamite is a polymorph with two other minerals, botallackite and paratacamite.
Polymorphs (a term that means "multiple forms") are minerals that have the same chemical composition--copper chloride hydroxide in the case of atacamite, botallackite, and paratacamite--but have different crystallographic structures.
[Jewelry making - Article 00411] - [Orchid] [Mineralogical Record] Atacamite in Selenite
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================================================================================ We are very proud that one of our best Mineral Specimens of ATACAMITE IN SELENITE from our LILY MINE (ICA-PERU) is in the cover of the last issue of the Mineralogical Record Magazine (May-June) In case some friend would like more details about it just let us know please.
