How to Care for Your Vintage Jewellery Part 5: Us vs. Verdigris
Verdigris is the green gunk that grows on your jewellery if you don’t properly clean and store your jewellery after you wear it. Like tarnish on silver, verdigris results from a process called oxidation. But when copper, brass or bronze is exposed to an oxidizing agent(say, an acidic elements such as sweat, cosmetics or vinegar), it causes a green-blue patina to form.
Verdigris rarely forms on gold or silver, but it can if it’s low grade (8 or 9 karat) that’s mixed lot of copper alloy. If left untreated, verdigris can “eat” away at the surface causing pitting. It also looks really gross.
How do you prevent it? I give all my jewels — costume or fine — a nice towel down with a microfibre cloth after wearing.
To clean it, fight acid with acid. If a piece has no stones, I soak it in vinegar for about 10 minutes, then, using a super soft toothbrush and mild cleanser give the jewel a good brushing. Corrosives can damage enamel, stones and non mineral gems such as pearls or coral. To target a specific area, I’ll dab on a bit of ketchup (because it stays in place and won;t spread to areas that don’t need cleaning) on the affected area. Let it sit for a while, then carefully clean it off with a Q tip. Always make sure the piece is dry before putting it away.