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  2. Pyrotechnic colorant - Wikipedia

    en.wikipedia.org/wiki/Pyrotechnic_colorant

    The red lithium flame leads to lithium's use in flares and pyrotechnics Copper compounds glow green or blue-green in a flame. Calcium compounds glow orange in a flame. Sodium compounds glow yellow in a flame. A pyrotechnic colorant is a chemical compound which causes a flame to burn with a particular color.

  3. Chemical coloring of metals - Wikipedia

    en.wikipedia.org/wiki/Chemical_coloring_of_metals

    Brown or black can be used as a base color for copper patina. If the amount of chlorides decreases the color will be more bluish-green, if carbonate decreases, more yellow-green. [27] Black for copper. Solution of sodium polysulfide 2.5%, items must be submerged in the solution after color developing, wash, dry and wax or varnish colored object ...

  4. Colored fire - Wikipedia

    en.wikipedia.org/wiki/Colored_fire

    Generally, the color of a flame may be red, orange, blue, yellow, or white, and is dominated by blackbody radiation from soot and steam. When additional chemicals are added to the fuel burning, their atomic emission spectra can affect the frequencies of visible light radiation emitted - in other words, the flame appears in a different color ...

  5. Black oxide - Wikipedia

    en.wikipedia.org/wiki/Black_oxide

    Black oxide for copper, sometimes known by the trade name Ebonol C, converts the copper surface to cupric oxide. For the process to work the surface has to have at least 65% copper; for copper surfaces that have less than 90% copper it must first be pretreated with an activating treatment. The finished coating is chemically stable and very ...

  6. Patina - Wikipedia

    en.wikipedia.org/wiki/Patina

    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 ...

  7. Flame test - Wikipedia

    en.wikipedia.org/wiki/Flame_test

    The flame test carried out on a copper halide. The characteristic bluish-green color of the flame is due to the copper. A flame test is relatively quick test for the presence of some elements in a sample. The technique is archaic and of questionable reliability, but once was a component of qualitative inorganic analysis.

  8. Copper(II) oxide - Wikipedia

    en.wikipedia.org/wiki/Copper(II)_oxide

    A black solid, it is one of the two stable oxides of copper, the other being Cu 2 O or copper(I) oxide (cuprous oxide). As a mineral, it is known as tenorite, or sometimes black copper. It is a product of copper mining and the precursor to many other copper-containing products and chemical compounds. [3]

  9. Kalai (process) - Wikipedia

    en.wikipedia.org/wiki/Kalai_(process)

    However, a chemical reaction between copper and oxygen called oxidization turns the copper vessels black. [7] Copper also reacts with the moisture in air and creates copper carbonate, which can be noticed as light green rust on the surface. Copper carbonate is poisonous and can make a person severely ill if it gets mixed with food. [7] The ...