Copper occasionally occurs native, and is found in many minerals such as cuprite, malachite, azurite, chalcopyrite, and bornite.  [c.62]

Azurite Anatase Beryl Braunite Biotite +12,2 to +19,0 +0,96 to +5,60 +0,4 +.35,0 to +150,0 +40,0 Lead Malachite Millerite Molybdenite Molybdenum -23 +10,5 to +14,5 +0,21 to +.3,85 +4,93 to +7,07 +89,0  [c.1793]

Lasur, /. azure azurite glazing, glaze. — m. lapis lazuli.  [c.271]

Copper has been used, especially in alloys with tin (bronze), since about 3(KX) b.c., and the Romans used it extensively. Small amounts of the free metal are found naturally, but its compounds (mostly sulphides) are abundant the most important ore is chalcopyrite or copper pyrites CuFeS. Other natural forms include the basic carbonates CuCOj. Cu(OH)2 (malachite) and 2CUCO3. Cu(OH)2 (azurite). The process of extraction consists essentially of (a) separation of the ore from rock, by flotation (selective wetting), (b) conversion of the su Iph ide ore to the crude metal, by blowing air through the molten ore. (c) purification of the crude metal, usually by electrolysis the crude copper is the anode in an electrolyte of acidified aqueous copper(II) sulphate, and the pure metal deposits on starting sheets of copper as cathode. The metal is extensively used for electrical purposes, for water tanks and pipes, and for roofing. Alloys include the bronzes containing tin. and sometimes phosphorus (for hardness— phosphor-bronze) brass, containing zinc and cupro-nickel (for coinage). Compounds of copper are used as fungicides, and as catalysts. Copper is found in plants and animals some lower animals (for example snails and crabs)  [c.408]

Altaite, see Lead telluride Alumina, see Aluminum oxide Alundum, see Aluminum oxide Alunogenite, see Aluminum sulfate 18-water Amphibole, see Magnesium silicate(2—) Andalusite, see Aluminum silicon oxide (1/1) Anglesite, see Lead sulfate Anhydrite, see Calcium sulfate Anhydrone, see Magnesium perchlorate Aragonite, see Calcium carbonate Arcanite, see Potassium sulfate Argentite, see Silver sulfide Argol, see Potassium hydrogen tartrate Arkansite, see Titanium(IV) oxide Arsenolite, see Arsenic(III) oxide dimer Arsine, see Arsenic hydride Auric and aurous, see under Gold Azoimide, see Hydrogen azide Azurite, see Copper(II) carbonate—dihydroxide (2/1)  [c.273]

In this experiment students synthesize basic copper(ll) carbonate and determine the %w/w Gu by reducing the copper to Gu. A statistical analysis of the results shows that the synthesis does not produce GUGO3, the compound that many predict to be the product (although it does not exist). Results are shown to be consistent with a hemihydrate of malachite, Gu2(0H)2(G03) I/2H2O, or azurite, GU3(0H)2(G03)2.  [c.97]

The corrosion processes for various metals are vasdy different, and hence the consequences for the object also differ greatly in nature. For bronze, for example, corrosion starts intergranulady. Cuprite (cuprous oxide) forms as the primary copper corrosion product. Because of the relatively large mobihty of copper ions, a cmst of cuprite forms on the surface and becomes the basis for continued chemical reactions resulting in the formation of products such as malachite and azurite, which are both basic copper carbonates. This corrosion cmst, also known as patina, stabilizes the system to a high degree, slowing the corrosion rate. Because the corrosion progresses slowly, and the copper ions migrate to the surface, the final effect is that the shape of the original surface is preserved, and can be brought to visibiUty through a careful removal of the corrosion cmst. Iron is vastly different. Here, oxides are formed in situ and, because of the enormous increase in specific volume of the corrosion penetrating into the interior, this process leads to serious changes in shape and, ultimately, complete disintegration of the object.  [c.425]

Of the seven metals known and widely used in antiquity, copper, gold, silver, tin, lead, iron, and mercury, only the first three occur naturally in the metallic state. The first extractive metallurgy process was probably used in the mountains of western Asia, in the areas that are now Iraq and Iran. There is tangible evidence of the smelting of copper (qv) by the Summerians and Egyptians as early as ca 4000 BC. Whereas discovery of the reduction of copper ore by fire was certainly accidental, the observation of the relationship between the blue azurite [1319-45-5] Cu(OH)2 2CuC02, or the green malachite [1319-53-5] Cu(OH)2 CuCO, and the red copper metal was a truly remarkable scientific discovery. Ancient peoples also knew how to treat copper sulfide ores.  [c.162]

Copper ore minerals maybe classified as primary, secondary, oxidized, and native copper. Primaryrninerals were concentrated in ore bodies by hydrothermal processes secondary minerals formed when copper sulfide deposits exposed at the surface were leached by weathering and groundwater, and the copper reprecipitated near the water table (see Metallurgy, extractive). The important copper minerals are Hsted in Table 1. Of the sulfide ores, bornite, chalcopyrite, and tetrahedrite—teimantite are primary minerals and coveUite, chalcocite, and digenite are more commonly secondary minerals. The oxide minerals, such as chrysocoUa, malachite, and azurite, were formed by oxidation of surface sulfides. Native copper is usually found in the oxidized zone. However, the principal native copper deposits in Michigan are considered primary (5).  [c.192]

Gopper(II) Carbonate Hydroxide. Basic copper carbonate, also named copper(II) carbonate hydroxide [12069-69-1], occurs ia nature as the green monoclinic mineral malachite. The approximate stoichiometry is CuC03-Cu(0H)2. There are two grades available commercially, the light and the dense. The light grade is produced by adding a copper salt solution to a concentrated solution of sodium carbonate, usually at 45—65°C. The blue, voluminous azurite [12070-39-2], C2H2Cu20g, forms initially and converts to the green malachite within two hours. The dense product can be produced by  [c.253]

Berg-arbeit, /. mining, -art, /. gang, matrix, vein stuff, -asche, /. an inferior kind of mineral blue, -balsam, m, petroleum, -bau, m. mining, -baukunde, /. science of mining, -blau, n. mineral blue, azurite. -braun, n. umber, -butter, /. (Min.) impure iron alum, iron sulfate or zinc sulfate, bergen, v.t. save, shelter, conceal, hide. — ge-borgen., p.a. safe well off,  [c.65]

See pages that mention the term Azurite : [c.49]    [c.83]    [c.83]    [c.417]    [c.419]    [c.192]    [c.57]    [c.74]    [c.65]    [c.265]    [c.265]    [c.271]   
Modern inorganic chemistry (1975) -- [ c.408 ]

The Nalco Guide to Cooling Water System Failure Analysis (1993) -- [ c.74 ]