Topics: Metal, Tarnish, Oxidation

Q.
Someone I know purchased a bracelet from an art gallery - it was silver and copper. She told me that the first time she wore the bracelet it got wet and the parts that were copper turned black. Why would this happen?
- Andrea
A.
Exposure to hydrogen sulphide (sulphur) can cause copper to oxidize and turn black. Healthy human sweat can contain sulphur, and moisture is also a contributor to color change. Copper oxidizes very quickly and the oxidation can usually be removed with heavy polishing.

To prevent oxidation, components can be sealed with a brush-on or spray-on fixative. Both Mona Lisa™ Metal Leaf™ top coat sealant and SpectraFix™ are good options.

- Michelle Wood, Jewelry-Making Expert

Materials

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