• Question: why does cheap jewellery go black/green

    Asked by 553smap45 to Sheila, Piyush, Natalia, Gary, Dimitar on 9 Nov 2018. This question was also asked by 278smap45.
    • Photo: Gary Munnelly

      Gary Munnelly answered on 9 Nov 2018:

      Oooh! Interesting! I don’t buy or own any jewellery, but I can take a guess! I reckon it is because cheap jewellery is made of copper. Copper is nice and shiny like gold, but much cheaper. When copper is exposed to air it oxidizes and turns a dark green colour.

    • Photo: Dimitar Shterionov

      Dimitar Shterionov answered on 11 Nov 2018:

      Precious metals like gold and silver and titanium do not oxidize as other, less expensive, materials do. Cheap jewelry which is made of other metals, e.g., copper, aluminum, bronze, brass, etc. oxidize much faster and change color.

      In addition, the sweat that the human body produces contains acid that further aids the oxidizing process.

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