Thread: Copper ruby
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Old 08-03-2019, 08:32 AM
Bradley Howes Bradley Howes is offline
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Location: Alfred University
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Bismuth and cyanide

Originally Posted by Pete VanderLaan View Post
It's curious. Bismuth is really a heavy metal right there with lead. It also uses cyanide. It also wants to use stannic, not stannous oxide which is an opacifier and not a reducing agent.

Honestly, I think black tin will yield better results. Bismuth also is not cheap. If anyone tries it, let us know.
This is now definitely on my to do list once I get back to Alfred and can do my GAE work again. My experience with bismuth thus far has been in calcedony. I was taking inspiration from Antonio Neri from ~1660 AD. He used mercury in his calcedony melts. Bismuth and mercury are part of a family defined by Volf that goes to the tune of Hg-Tl-Pb-Bi (80-83 on the periodic table). I made my own bismuth oxide from bismuth metal by reacting it with nitric acid and reducing it to oxide with sodium hydroxide. The amounts I was using though was over the .31 wt.% limit specified in the patent that produces browns and blacks from the formation of bismuth metal particles. (Side note: I once saw a wonderful honey amber orange brown color made from bismuth by one of the Alfred undergrad engineering seniors.) It might be worth revisiting that avenue.

I’m very suspicious of the cyanide. I’ve never used it and I have no idea if it volatilizes from the melt somehow. I also have no idea what role the cyanide plays in the glass. Is it some kind of reducing agent?

Last edited by Bradley Howes; 08-15-2019 at 03:51 PM.
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