Cuprites

Copperil) oxide, CujO, occurs naturally as the red cuprite. It is obtained as an orange-yellow precipitate by the reduction of a copper(II) salt in alkaline solution by a mild reducing agent, for example glucose, hydroxylamine or sodium sulphite ... 

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

Cryolite, see Sodium hexafluoroaluminate Cryptohalite, see Ammonium hexafluorosilicate Cupric and cuprous, see under Copper Cuprite, see Copper(I) oxide... 

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). 

Kupfer-asche, /. copper scale, -azetat, n. copper acetate, -azetylen, n. copper acetylide. -bad, n. copper bath, -barre, /. copper bar copper ingot, -belze, /. copper mordant, -blatt, n. copper foil, -blau, n. blue verditer, azurite. -blech, n. sheet copper, copper foil, -blel, n. copper-lead alloy, -bleiglanz, m. Min.) cuproplumbite. -bleivitriol, m. linarite. -blende, /. tennantite. -blute, / copper bloom (capillary cuprite), -braim, n. tils ore (earthy ferruginous cuprite),... 

Rot-kali, n. red prussiate of potash (potassium ferricyanide). -kiefer,/. red pine, -klee, m. red clover, -kohl, m. red cabbage, -kohle, /. red charcoal, -kupfer, -kupfererz, n. red copper, red copper ore (cuprite), -lauf, m. erysipelas. 

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. 

Whereas cuprite is red, tenorite is black, showing that there is some electron mobility in this crystal resonance... 

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. 

Oxides and hydroxides Cuprite, uraninite, baddeleyite, corundum, haematite, rutile, cassiterite, brucite, diaspore, goethite, limonite... 

The structure of Cu20 (cuprite). Eight unit cells are shown they correspond to one unit cell of cristobalite if only one of the two networks is present. The gray network has no direct bonds to the black network (stereo image) R... 

Test measurements were performed on Cuprite, Cu20, for various reasons it has a well-known structure (cubic, space group Pn3m, a = 4.2696, Z = 2) and has been examined by conventional X-ray single crystal diffractometry [5, 6] and by synchrotron radiation in the Tow energy regime [7]. As a consequence of the... 

We thank K. Eichhom for providing the source code of DIF4, Th. Kracht for help with the adaptation of the software to SPECTRA ON LINE, and H.-G. Krane for providing the cuprite sample. 

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). 

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