I have several antique pins and brooches. The obvious ones are marked 925 but there are many that are not marked. None of them stick to magnets and all are heavy for their size. And, as far as I can see, none of the metal has been chipped away to expose a possible secondary metal underneath.
I do have one piece, however, that seems to be tarnished in a small area, but will not come off with my polishing cloth. It doesn't stick to a magnet either. How can I tell if they are the real thing?
Also, will testing it damage the jewelry - especially if it's not real silver? If they're not silver, what metal could they possibly have used that won't stick to a magnet?
Related posts:
1 response so far ↓
1 Sketcher // May 3, 2008
Hi!
Only iron and iron alloys stick to a magnet. The base metal in plated jewelry is usually a copper alloy that contains various other metals such as tin and nickel.
You could look up a silversmith (or goldsmith) and ask them to test your pieces. One way to do this is to scrape a tiny amount of metal from an unobtrusive place in the piece. That way s/he can tell if the piece is plated. Then s/he'll put a drop of nitric acid on the scrapings to tell the purity of the silver.
The piece that's tarnished might have been further plated with rhodium, a metal that increases the luster of silver and provides a durable coating. The coating might have worn off and left a spot that stands out. Also, it could be that the piece is base metal, and the silver plating has worn off. Copper alloys oxidize (blacken) easily, that's why copper and bronze jewelry have to be protected by a special lacquer.
I hope this helps. Good luck!
Leave a Comment