Wood fired Wedding ring
December 7, 2023 2:55 PM Subscribe
I have a tungsten carbide wedding ring. I accidentally cooked it in a wood fired stove. What is it's new patina made from?
lost it a few days ago and realised that it must have fallen off whilst I was building a fire in a wood burning stove.
I poked about the ashes and found it basically unscathed. However the ring now has an interesting patina of dark greys with a sort of marbling of yellow patches. It's baked in pretty solid.
What might the composition of this patina be?
What are the yellow bits?
I assume I can just get it polished to return it to shiny tungsten carbide if I wanted. I might just leave it though, because it's quite interesting and pretty, but if I do is it likely to be skin safe?
I'm mainly interested in the general chemistry of it's new coating.
lost it a few days ago and realised that it must have fallen off whilst I was building a fire in a wood burning stove.
I poked about the ashes and found it basically unscathed. However the ring now has an interesting patina of dark greys with a sort of marbling of yellow patches. It's baked in pretty solid.
What might the composition of this patina be?
What are the yellow bits?
I assume I can just get it polished to return it to shiny tungsten carbide if I wanted. I might just leave it though, because it's quite interesting and pretty, but if I do is it likely to be skin safe?
I'm mainly interested in the general chemistry of it's new coating.
Can we see a picture? I won't be able to help identify it but your description is interesting!
posted by bensherman at 3:56 PM on December 7, 2023 [5 favorites]
posted by bensherman at 3:56 PM on December 7, 2023 [5 favorites]
Typically in jewelry it's call firescale and that's the colorful result of the oxidation of copper. Copper is found in all sorts of jewelry alloys and solders. But your ring is not an alloy - it's likely a cemented carbide* and more like a fancy ceramic.
Regardless the tungsten part is not very reactive so any discoloration is very unlikely to be a result of the oxidation of the metal. Plus tungsten has got a really high melting point - it's well past 3,000 °C and so a wood fire would need to be 3 times hotter.
My wild guess is that scale on your ring is essentially a wood ash glaze, which can produce yellow surfaces. That's likely superficially bonded/damaged the carbon part of the matrix. A proper jewelry outfit should be able to resurface your ring with their special polishing kit - nothing short of gear that can polish a diamond will be able to touch your ring.
*I was in the biz for a bit but never got to work with any tungsten carbide.
posted by zenon at 6:21 PM on December 7, 2023 [12 favorites]
Regardless the tungsten part is not very reactive so any discoloration is very unlikely to be a result of the oxidation of the metal. Plus tungsten has got a really high melting point - it's well past 3,000 °C and so a wood fire would need to be 3 times hotter.
My wild guess is that scale on your ring is essentially a wood ash glaze, which can produce yellow surfaces. That's likely superficially bonded/damaged the carbon part of the matrix. A proper jewelry outfit should be able to resurface your ring with their special polishing kit - nothing short of gear that can polish a diamond will be able to touch your ring.
*I was in the biz for a bit but never got to work with any tungsten carbide.
posted by zenon at 6:21 PM on December 7, 2023 [12 favorites]
As for safety - I would wear it with is new glazed finish without second thought.
posted by zenon at 6:25 PM on December 7, 2023 [3 favorites]
posted by zenon at 6:25 PM on December 7, 2023 [3 favorites]
Response by poster: Sorry for the tremendous delay. I finally took a photo and put it somewhere accessible.
Wood Fired Tungsten
Further Wood Fired Tungsten
It's a little brighter in real life, and has faded a bit since it occurred, but I think you can get an idea of how it looks.
posted by Just this guy, y'know at 5:21 PM on December 28, 2023
Wood Fired Tungsten
Further Wood Fired Tungsten
It's a little brighter in real life, and has faded a bit since it occurred, but I think you can get an idea of how it looks.
posted by Just this guy, y'know at 5:21 PM on December 28, 2023
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posted by It's Never Lurgi at 3:06 PM on December 7, 2023