Minerals cuprite

Shakudo. Shakudo is a copper alloy used in Japan since the third century b.c.e. for making decorative and ornamental objects. In addition to copper it also includes gold (1—4%), silver (about 2%), and lead (about 1%). Occasionally gold replaced part or even all of the silver. Exposed shakudo surfaces acquire a layer of patina consisting mainly of the mineral cuprite (composed of cuprous oxide), which exhibits a characteristic shine. Varying amounts of gold in the alloy are said to have a marked effect on the color and the shine (Notts 1988 Oguchi 1983). 

Copper is distributed widely in nature as sulfides, oxides, arsenides, arsenosulfides, and carbonates. It occurs in the minerals cuprite, chalcopyrite, azurite, chalcocite, malachite and bornite. Most copper minerals are sulfides or oxides. Native copper contains the metal in uncombined form. The principal copper minerals with their chemical compositions and percentage of copper are listed below ... 

Copper(I) oxide occurs in nature as the mineral cuprite. 

Copper(I) oxide is found in nature as the mineral cuprite. Copper(I) oxide can be prepared by several methods, which include ... 

Elemental composition Cu 88.42%, 0 11.18%. The oxide may be dissolved in excess hydrochloric acid, diluted appropriately and analyzed by AA or ICP techniques (see Copper). The mineral cuprite may be identified nondestruc-tively by various x-ray methods. 

CUPRITE. The mineral cuprite, cuprous oxide. Cu 0. occurs as isometric crystals, usually octahedrons, hut may he cubes, dodecahedrons or modified combinations, it also is found as a massive, earthy material. Its fracture is conchoidal to uneven brittle hardness,, 1.5-4 specific gravity, 6.14 luster, submetallic to earthy color, red nearly transparent to nearly opaque. Its streak is shining brownish-red. Cuprite is a secondary mineral resulting doubtless from the oxidation of copper sulfides. It is often found associated with native copper, malachite and azurile. 

Cuprous oxide, Cu20.—This oxide occurs as the mineral cuprite or ruby copper. It is formed by reduction of alkaline solutions of complex cupric salts with a reducing sugar, such as dextrose, an example being the reduction of Fehling s solution,8 the oxide being deposited as a red, crystalline powder. 

Structures based on systems of interpenetrating diamond nets. In the structures we have been describing it is possible to trace a path from any atom in the crystal to any other along bonds of the structure, that is, along C-C bonds in diamond, Si-O-Si bonds in cristobalite, etc. In CU2O (the mineral cuprite) each Cu atom forms two collinear bonds and each 0 atom four tetrahedral bonds, and these atoms are linked together in exactly the same way as the 0 and Si atoms... 

Calculate the percentage of copper in each of the following minerals cuprite, CU2O copper pyrites, CuFeSa ... 

Cuprous Oxide. Red copper oxide C.I. 77402 Perenex Yellow Cuprocide Copper-Sandoz Caocobre. CujO mol wt 143.08. Cu 88.82%, O 11.18%. Occurs in nature as the mineral cuprite (red to reddisli-brown octahedral or cubic crystals). Prepd commercially by furnace reduction of mixtures ot copper oxides with Cu Drapeau, Johnson, U.S. pats. 2,758,014 2,891,842 (1956, 1959 to Glidden) by decompn of copper ammonium carbonate Rowe, U.S. pat. 2,474,497 Klein, U.S. pat. 2.474,533 (both 1949 to Lake Chemical) Rowe, U.S. pat. 2,536,096, Munn, U.S. pat. 2,670,273 (1951, 1954 to Mountain Copper) by treatment of Cu(OH)j with S02 Rowe, U pat. 2,665,192 (1954 to Mountain Chemical) or by electrolysis of an aq soln of NaCI between Cu electrodes Arend, Paint Technology 13, 265 (1948). Laboratory prepns Glemser, Seuer in Handbook of Preparative Inorganic Chemistry, vol. 2, G. 

Copper(I) oxide occurs naturally as the mineral cuprite. It forms when native copper (copper as an element) is exposed... 

See if you can name the common mineral cuprite, CU2O, in the common systen. For a picture of a sample of cuprite see Figure 6. 

Cuprous (copper) oxide n. CU2O. Occurs in nature as the mineral, cuprite. Prepared commercially by furnace-reduction of a mixture of cupric oxide and copper. Used as a toxin in anti-fouling compositions. 

There are very few examples of coordination polymers in which ligands alone act as nodes i.e., the metal is effectively acting as a linear spacer. A naturally occurring example is the mineral cuprite. Cuprite exists as a twofold diamondoid network with oxygen atoms acting as tetrahedral nodes and Cu cations acting as linear spacers. However, one of the networks sustained by tpt could be regarded as an example of a coordination polymer of this type. The spectacular structure of... 

Although most of the aqueous chemistry of copper involves the +2 oxidation state, there are a number of important compounds of coppeifl). When copper is heated in oxygen below 1000°C, it forms the black copper(II) oxide, CuO. But above this temperature, it forms the brick-red copper(I) oxide, CU2O. This oxide is found naturally as the mineral cuprite. 

Elements in nature can be found in different oxidation states. For example, the mineral cuprite has the formula Cu O. By rule 6, copper is in the +1 oxidation state. Malachite, on the other hand, has the formula CUjCOjlOHjj. Given that carbon is in the +4 state, each oxygen is in the -2 state, and each hydrogen is in the +1... 

Copper occasionally occurs native, and is found in many minerals such as cuprite, malachite, azurite, chalcopyrite, and bornite. 

Copper Oxides. Coppet(I) oxide [1317-39-17 is a cubic or octahedral naturally occurring mineral known as cuprite [1308-76-5]. It is ted or reddish brown in color. Commercially prepared coppet(I) oxides vary in color from yellow to orange to ted to purple as particle size increases. Usually coppet(I) oxide is prepared by pytometaHutgical methods. It is prepared by heating copper powder in air above 1030°C or by blending coppet(II) oxide with carbon and heating to 750°C in an inert atmosphere. A particularly air-stable coppet(I) oxide is produced when a stoichiometric blend of coppet(II) oxide and copper powder ate heated to 800—900°C in the absence of oxygen. Lower temperatures can be used if ammonia is added to the gas stream (27-29). 

Cuprite (CuO) is formed as a black, nonmagnetic mineral under boiler conditions. The copper originates from brasses and cupronickels used in condensers and FW heaters. 

Cuprite CuO Black non-magnetic mineral. Originates from condensers and FW heaters. 

Nearly all transition metals are oxidized readily, so most ores are compounds in which the metals have positive oxidation numbers. Examples include oxides (Ti02, mtile Fc2 O3, hematite C112 O, cuprite), sulfides (ZnS, sphalerite M0S2, molybdenite), phosphates (CeP04, monazite YPO4, xenotime both found mixed with other rare earth metal phosphates), and carbonates (FeC03, siderite). Other minerals contain oxoanions (MnW04, wolframite) and even more complex stmctures such as camotite, K2 (002)2 ( 4)2 2 O ... 

A single metal may be extracted from several minerals. Thus there are many minerals of copper, such as chalcocite, bornite, chalcopyrite, cuprite, native copper, and malachite one or more of these may occur in an individual deposit. Also, more than one metal may be obtained from a single mineral stannite, for example, yields both copper and tin. A mineral deposit, therefore, may yield several metals from different minerals. 

Copper oxide mixed ore - Type 2. In contrast to Type 1, this ore type contains cuprite, malachite and azurite as the main copper oxide minerals. This ore type predominantly contains carbonaceous gangue, and usually, significant amounts of clay-like slimes. 

Mixed copper sulphide oxide ores. These contain varieties of both sulphide and oxide minerals, and are the most complex copper-bearing ores from a beneficiation point of view. The major copper minerals present in this ore type include bomite, chalcocite, covellite, malachite, cuprite and chrysocolla. In some cases, significant amounts of cobalt minerals are also present in this ore. 

In a number of oxide ores, cuprite (Cu20, Cu = 88.8%, SG = 5.9) is present as secondary minerals together with sulphides, malachite and tenorite. Cuprite can be floated using either sulphidization or anionic flotation methods. The flotation properties of cuprite are somewhat different from that of malachite. For example, using a sulphidization method for flotation of cuprite requires higher dosages of sulphidizer. 

Some ore deposits contain cuprite as the principal mineral. Typically, these deposits contain appreciable amounts of slimes and clay minerals. The laboratory studies conducted on these types of ore indicated that improved metallurgical results can be achieved using the sulphidization method with ester-modified xanthate [8]. 

The mixed sulphide oxide ores usually contain two or more oxide minerals, including cuprite, malachite and tenanntite. The sulphide copper minerals are represented by covellite and bomite. Examples of this type of operation are located in the former Republic of Zaire (Komoto, Dima 1 and 2 plants), and the Nchanga open pit plant in Zambia. 

Copper is the 26th most abundant element on Earth, but it is rare to find pure metallic deposits. It is found in many different types of mineral ores, many of which are close to the surface and easy to extract. It is found in two types of ores (1) sulfide ores, such as covellite, chalcopyrite, bornite, chalcocite, and enargite and (2) oxidized ores, such as tenorite, malachite, azurite, cuprite, chrysocolla, and brochanite. 

SQWVs of green paint layers confirmed the presence of azurite and azurite plus smalt mixtures accompanied by tenorite (CuO) in several samples as a result of thermal decomposition of azurite. Since azurite decomposition starts at 345°C with a loss of CO2 and water, slowly yielding CuO which is then converted to cuprite (Cu2 O) at 840°C [175], and since no traces of this last mineral were detected in any sample, one can conclude that the effective temperature reached by the pigments in such samples ranged from 350 to 840°C. 

It is a secondary mineral found associated with malachite and cuprite originally found at Atacama, Chile, whence its name. Other localities are Bohemia, South Australia, and in the United States in Arizona, Utah, and Wyoming. See also Cuprite and Malachite. 

Cuprite is a fairly common mineral, and of the many localities in which it occurs may be mentioned the Province of Perm, in the former U.S.S.R.. Chessy, France Broken Hill. New South Wales Corocoro. Bolivia Andacollo, Chile Bisbee. Arizona and Del Norte County, California. Magnificent large transparent red gem crystals, some with a coating of malachite, have been found at Ojunga. S.W. Africa. The name cuprite is derived from the Latin cuprum, copper. 

PSEUDOMORPH. In mineralogy and geology, a mineral, having the crystal form of one species and the chemical composition of another. Typical pseudomorphs are malachite in the form of cuprite, barite in the form of quartz, limonite in the form of pyrite. In such cases of pseudomorphism the evidence seems to be that there has been a complete chemical and molecular change but without any change of the original outward form. See also Mineralogy. 

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