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Russian Gemstones Encyclopedia

Vladimir Bukanov. Russian Gemstones Encyclopedia

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

CHRYSOCOLLA


CHRYSOCOLLA (Chrysocoll—Chrysocolle—’ризоколла) Theophrastus (372-287 B.C.), from Gk. “chrysos” – gold and “kola” – glue, referring to its usage as a flux in soldering gold. Term is used from antiquity.

Composition & Properties. Silicate ~ Cu4H4[(OH)8|Si4O10]·nH2O, orthorhombic system. Hardness 2-4. Density 2-2.4. Glass luster to dull one. Fragile. Chrysocolla is found as cryptocrystalline accumulations in the form of kidney-shaped aggregates. Color: light blue to blue, with admixture of kaolinite – pale blue. The color of cuprian wad, or lampadite is brownish to black because of the admixture of manganese. Transparent to non-transparent. Chrysocolla is developing in the form of pseudomorphs on azurite, dioptase, cuprite, malachite, forming cuprite chrysocolla, or malachite chrysocolla. Sometimes, it is represented in quartz or chalcedony as admixture, forming an ornamental variety of quartz chrysocolla, or jeweler’s chrysocolla – azurchalcedony, which are called also malachite chert or siliceous malachite. Mixture of azurite with chrysocolla is called copper lazur, with epidoteasperolite, with halloysite – pilarit.Mixture of chrysocolla with malachite and tenorite forms melanochalcite. Under dehydration chrysocolla is transferring into planchéite and shattuckite. It is processed in cabochons and flat insets as malachite.

Deposits. It is widespread at many copper mines, rarely displaying jewelry quality. In Russia, in the Urals, at the Mednorudnyianskiy mine, near Nizhniy Tagil, light bluish-green crusts of chrysocolla on malachite were described as demidovite. This variety was classified as the most expansive kind of malachite. In Transbaikalia, at the Udokan copper deposit, near the settlement of Chara, they discovered significant accumulations of chrysocolla. In Kazakhstan, chrysocolla is extracted not far from Zhezkazgan (now Zhezkazgan). In Tadzhikistan, at the Chorukh-Dayron deposit, near Khodzhent, chrysocolla was discovered in the form of sphaerolites in clusters with calcite. From that deposit there is a piece of ore of bright blue chrysocolla, 40x50 cm. in size, in the Fersman’s Museum, Moscow.

In the south of Israel, an ornamental stone is mixture of chrysocolla with turquoise and malachiteEilath stone from the Eilat deposit near the Akaba Gulf. In Germany chrysocolla from the Schist Mts. near Dillenburg, Hessen, has the local name dillenburgite. In Romania, chrysocolla in the form of crusts or sphaerolites is often found at the copper deposits Moldova Nouvâ and Ocna de Fier; in the form of kidney-shaped aggregates – at the deposits Sasca Montanâ  and Bâita Bihor, or in the form of stalactites – at the Oravi¸ ta deposit, Cara¸ ¸ s-Severin Dept. In Italy, on the Sardinia Is., near Arenas, blue mixture of chrysocolla with gibbsite is called traversoite. In Congo (form. Zaire), at the Katanga Prov., glassy dark green chrysocolla is known under the trade name katangite. In India, in the Karnataka State, mixture of malachite with chrysocolla and calcite is called maysorin, after the discovery location near Maysor town. In Australia, at the Elliot Stone deposit, the Northern Territory, they extract nodules of chrysocolla quartz – azurlite of light bluish-green color with veins of goethite, resembling cobweb turquoise.

In the U.S.A., it is known at the Copper World Mine, California, as well as in Wyoming, Nevada; and in Arizona they extract quartz chrysocolla. In Canada, chrysocolla is found in copper ores of the Allowns Mine on Superior Lake. In Mexico and in the U.S.A., ornamental chrysocolla has the trade name psilomelane. In Chile, chrysocolla is extracted at the Chuquicamata deposit, Antofagasta Prov.; in Copiapó Dist., Atacama Prov.; and in the Coquimbo Prov., where it is called llanca. In Peru, chrysocolla mined for jewellery purposes at the Acarí mine, near Nazca, Arequipa Dept., and at the Lily mine, Ica Dept.; also chrysocolla chalcedony and green Andean opal, colored with chrysocolla were found.

Synonyms. Alumochrysocolla | Bogoslovskite, after the deposit at the Urals, Russia | Chalcostaktite |~ Chrysocolla: Arizona ~, copper ~, Mexican ~, Peruvian ~| Siliceous copper | Cornuite, after the Austral. mineralogist F. Cornu | Cyanochalcite | Demidovite, after the Russ. businessman A.N. Demidov | Goldleim, by Agricola, Old Russ zlatokley | Copper green | Malachite green | Dushan jade, from China | Lampadite, after the Germ. researcher W. Lampadius | Copper malachite | Malachitkiesel, Germ. | Pitch copper ore | Slaggy copper ore | Green ore | Resanite, after Don Pedro Resano from Puerto Rico, the U.S.A. | Sommervillite, after the Somerville despoit, New Jersey, the U.S.A. | Green spar. | Green stone | Traversoite, after the Ital. engineer G.B. Traverso | Rock verde.

Similarity. Chrysocolla looks like azurite, aurichalcite, turquoise, variscite, malachite and shattuckite. Sometimes they take its colloidal analogue – cornuite for chrysocolla, it is half-transparent copper silicate of green to light blue-green color.

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