I think it’s important to educate consumers about jewelry. The techniques, the materials and so much more! Without further ado, here’s a quick explanation of firescale.
Heating metal causes copper oxides to rise and mix with the air to create a purple, gray or blue color on the surface of the metal. It happens if the metal contains copper (even gold with a high copper content).
“Copper in my silver?!” you exclaim.
“In my gold?!” you continue to exclaim.
Yep, copper is in there. It’s an alloy. Here’s my blog post about gold. It will help explain the metal alloy thing.
As for sterling silver: sterling silver alloy is made up of 92.5% pure silver and 7.5% copper or other metals.
Sometimes the firescale isn’t that obvious, but there it is nonetheless. It might not be a big deal to some. Maybe it’s barely noticeable, or on the back of a pendant, or inside a ring. Well, if firescale is left on the piece it will oxidize faster than the rest of the piece. It will become more noticeable over time. If the piece has a shiny finish this can be a real problem.
There are steps we metalsmiths take to cut down on firescale and ways to remove it.
If heat control and flux don’t work, you have to figure out how to get rid of the firescale. Your options are:
There is so much involved in making jewelry! The obvious, is creativity and artistry, but there is math, chemistry and physics too.
Here are some sterling rings sans firescale of course!