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Patina (/ p ə ˈ t iː n ə / pə-TEE-nə or / ˈ p æ t ɪ n ə / PAT-ih-nə) is a thin layer that variously forms on the surface of copper, brass, bronze, and similar metals and metal alloys (tarnish produced by oxidation or other chemical processes), or certain stones [1] and wooden furniture (sheen produced by age, wear, and polishing), or ...
Malachite is a copper carbonate hydroxide mineral, with the formula Cu 2 CO 3 (OH) 2.This opaque, green-banded mineral crystallizes in the monoclinic crystal system, and most often forms botryoidal, fibrous, or stalagmitic masses, in fractures and deep, underground spaces, where the water table and hydrothermal fluids provide the means for chemical precipitation.
The Statue of Liberty, showing advanced patination; verdigris is responsible for the statue's iconic green colour.. Verdigris (/ ˈ v ɜːr d ɪ ɡ r iː (s)/) [1] is a common name for any of a variety of somewhat toxic [2] [3] [4] copper salts of acetic acid, which range in colour from green to a bluish-green depending on their chemical composition.
Oxide jacking has caused concrete spalling on walls of the Herbst Pavilion at Fort Mason Center in San Francisco. The expansive force of rusting, which may be called oxide jacking or rust burst, is a phenomenon that can cause damage to structures made of stone, masonry, concrete or ceramics, and reinforced with metal components.
The oxidation states are also maintained in articles of the elements (of course), and systematically in the table {{Infobox element/symbol-to-oxidation-state}}
After the Second World War, there was a growing interest in green patinated copper sheets, which were intended primarily for architectural use. [18] [19] [20] Technologies for anodic oxidation of titanium, and later niobium and tantalum, have evolved since the mid-1960s. Technology for the anodic oxidation of stainless steel was developed too ...
The industrial catalyst is obtained from finely ground iron powder, which is usually obtained by reduction of high-purity magnetite. The pulverized iron metal is burnt (oxidized) to give magnetite or wüstite of a defined particle size. The magnetite (or wüstite) particles are then partially reduced, removing some of the oxygen in the process ...
Chamosite is an olive-green color in thin section that readily oxidizes to limonite. When it is partially or fully oxidized to limonite, the green color becomes a yellowish-brown. Limonite is opaque under the microscope as well. Chamosite is an iron silicate and it has a birefringence of almost zero.