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  2. Tarnish - Wikipedia

    en.wikipedia.org/wiki/Tarnish

    Tarnish is a surface phenomenon that is self-limiting, unlike rust. Only the top few layers of the metal react. The layer of tarnish seals and protects the underlying layers from reacting. Tarnish preserves the underlying metal in outdoor use, and in this form is called chemical patina. [2]

  3. Silver sulfide - Wikipedia

    en.wikipedia.org/wiki/Silver_sulfide

    It constitutes the tarnish that forms over time on silverware and other silver objects. Silver sulfide is insoluble in most solvents, but is degraded by strong acids. Silver sulfide is a network solid made up of silver (electronegativity of 1.98) and sulfur (electronegativity of 2.58) where the bonds have low ionic character (approximately 10%).

  4. Conservation and restoration of silver objects - Wikipedia

    en.wikipedia.org/wiki/Conservation_and...

    Silver is known in the chemistry world as a noble metal, which means it is resistant to corrosion, but not completely immune. Whether silver plating or pure silver, the composite of the metal will tarnish when exposed to air and sulfur. Tarnish is a chemical reaction on the surface of metal (copper, brass, silver, etc.) and causes a layer of ...

  5. Silver - Wikipedia

    en.wikipedia.org/wiki/Silver

    The chemical symbol Ag is from the Latin word for silver, argentum (compare Ancient Greek ἄργυρος, árgyros), from the Proto-Indo-European root *h₂erǵ-(formerly reconstructed as *arǵ-), meaning ' white ' or ' shining '. This was the usual Proto-Indo-European word for the metal, whose reflexes are missing in Germanic and Balto-Slavic.

  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. Gold plating - Wikipedia

    en.wikipedia.org/wiki/Gold_plating

    Gold plated silver jewellery can still tarnish as the silver atoms diffuse into the gold layer, causing slow gradual fading of its color and eventually causing tarnishing of the surface. This process may take months and even years, depending on the thickness of the gold layer.

  8. Chalcopyrite - Wikipedia

    en.wikipedia.org/wiki/Chalcopyrite

    Chalcopyrite (/ ˌ k æ l k ə ˈ p aɪ ˌ r aɪ t,-k oʊ-/ [7] [8] KAL-kə-PY-ryte, -⁠koh-) is a copper iron sulfide mineral and the most abundant copper ore mineral. It has the chemical formula CuFeS 2 and crystallizes in the tetragonal system.

  9. Lead - Wikipedia

    en.wikipedia.org/wiki/Lead

    Lead (/ l ɛ d /) is a chemical element; it has symbol Pb (from Latin plumbum) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cut, lead is a shiny gray with a hint of blue. It tarnishes to a dull gray color when exposed to ...