|
I do not know. It's a good question for John. I can say that I've certainly seen lots of iridescence on green bottle glasses that have solarized and I think them to be chrome based. I do know that the EU has become concerned with Chrome leaching from glass in landfills.
I've always thought of lead glasses as allowing what I would call "packing " of metallic oxides into glasses. When making the black, extra lead has to go into the goop to get the metals into solution. My black has a significant addition of chrome. I grind it finely with lithium and sodium before it goes in the mixer. I don't think of 2% as being a small addition at all. Chrome seems capable of causing significant expansion shift as well.
__________________
Where are we going and why am I in this basket?
|