Cuprite elements

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. 

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. 

In 1826 Carl Kersten of Gottingen detected selenium in the capillary cuprite or so-called copper bloom from Rheinbreitenbach on the Rhine, which Councilor Hausmann had presented to him (39). He also found this element to be present in the earthy ferruginous cuprite (tile ore) from the same locality (39). 

In addition to the analysis of physical structural characteristics of textile fabric pseudomorphs, chemical information has been obtained. On bronze and copper artifacts, the pseudomorphs are composed of malachite, tenorite, and cuprite (I, 2), the formation of which probably requires moist conditions, a corrosive metal, and optimum fiber-metal contact (I). Trace elements in their structure vary from object to object and site to site (1-3), but the relationship of these elements and the fiber, metal, and soil composition is not yet known. 

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

Copper s relative abundance in the Earth s crust is about 50 mg/kg (i.e., ppm wt.), which is less than nickel and zinc. It occurs as a native element (4%), but the major part of its occurrence is as oxides minerals (10%) such as cuprite [Cu O, cubic] carbonates (5%) malachite [CuC03.Cu(OH)j, monoclinic] and azurite [2CuC03.Cu(0H)j, monoclinic] sulfide minerals (80%) chalcocite [Cu S, monoclinic], chalcopyrite [CuFeS, tetragonal], and bornite [CUjFeS, cubic] and in other rare minerals (1%) such as atacamite [CUjC OH), orthorhombic]. But only the oxide and sulfide minerals are used industrially as copper ores. Chile is the world s largest producer of copper, followed by the United States. 

Natural occurrence. Oxygen is the most abundant chemical element in the Earth s crust with 46.1 wt.% mostly combined as silicates (e.g., quartz and silica, feldspars and feld-spathoids, zircon), carbonates (e.g., calcite, dolomite, siderite) and oxides (e.g., hematite, rutile, zincite, cuprite), while it forms 20.65 vol.% of the air and 89 wL% of the ocean water. 

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... 

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