Jewellery
A rare household object where cleaning it is subtractive. Every polish takes metal away, and on anything plated there is a finite amount to take.
Start here
What this is, what tends to go wrong with it, and what to do about it.
Made from
What tends to go wrong
Unlike a stain, tarnish is made of the very surface it sits on. Removing it always removes metal.
Why it is difficult: Coating thickness
- Skin oil· no established method
The soil that arrives everywhere a person touches, gets darker as it ages, and is the reason a clean-looking surface still feels tacky.
The science behind this: Where tarnish actually comes from, Polishing removes metal, Coating thickness
In detail
Conservation guidance states what no retailer page does: cleaning and polishing REMOVE ORIGINAL METAL. That reorganises the whole question. A piece polished monthly is being consumed, and the wish behind the habit — for metal to be bright — is named as the commonest cause of over-cleaning. Metal cleaners compound it, because they may leave residues that generate further corrosion. On a plated piece the arithmetic is brutal. Plating is a finite thickness, and a conservation leaflet on vehicle brightwork says nickel-plated surfaces can be very thin and are probably already worn thin from previous polishing. There is no way to put it back. So the useful routine is preventive. Handle it less, and where it has been handled a jeweller's cloth will buff fingerprints off uncoated metal — one with NO abrasive, relying on the stiffness of its weave. Store it away from sulphur, the strongest tarnishing agent, which comes out of wool, felt, foam rubber and paint as well as city air. A wool-lined box is a tarnishing environment. Where a piece is set with stones, pearls or shell, or where the composition is uncertain, the conservation answer is a specialist rather than a method.
What works
Detergent is safe on, in specific conditions, Jewellery
Safe only in specific conditions
This is only appropriate within specific limits, and nothing is established outside them.
Only within these limits:
- Warm water with a little mild detergent, a soft brush, and dried thoroughly
- NOT where the piece is set with stones, pearls or shell, or where the composition is uncertain — that is a specialist's question
- No polish, no dip and no impregnated cloth on anything plated
The mildest thing that works is the right thing every time here, because the alternative is subtractive: cleaning and polishing remove original metal, and on plate there is a finite amount to remove.
Precautions
- Test on an inconspicuous area first
Evidence
Supported
Sources
Museum Handbook Part I, Appendix O: Curatorial Care of Metal Objects
National Park Service, US Department of the Interior, 2002 · Reference work
Relied on for: That cleaning and polishing remove original metal, that proprietary cleaning products contain ammonia, weak acids or bases, solvents, waxes and fats that may adversely affect metal objects, and that a non-abrasive cloth is preferred for fingerprints. (states this directly)
Caring for your collections: Silver and plate
The Institute of Conservation (Icon) · Trade or professional body
Relied on for: That where the composition of a piece is uncertain it goes to a specialist before anything is attempted. (states this directly)
Why
- Jewellery is explained by Where tarnish actually comes from
Related
- Jewellery is made from Gold
- Jewellery is made from Gold plate and vermeil
- Jewellery is made from Sterling silver
- Jewellery is commonly affected by Tarnish
- Jewellery is commonly affected by Skin oil
Sources for this page
Sources
Museum Handbook Part I, Appendix O: Curatorial Care of Metal Objects
National Park Service, US Department of the Interior, 2002 · Reference work
Relied on for: That cleaning and polishing remove original metal, that over-cleaning comes from wanting metals bright, that metal cleaners may leave residues generating further corrosion, that sulfur compounds are the strongest tarnishing agents and come from foam rubber, carpet padding, paints, wool and felt, and that a jeweller's cloth containing no abrasive may buff fingerprints from uncoated metal. (states this directly)
Caring for your collections: Silver and plate
The Institute of Conservation (Icon) · Trade or professional body
Relied on for: That where the composition of a piece is uncertain the reader is directed to a specialist rather than to a method. (states this directly)