I used to have a graphic w/info., but can't find it offhand.
However, Google brought up a batch of things in answer to What makes glass different colors. Among them:
https://en.wikipedia.org/wiki/Glass_...%20to%20yellow.
https://geology.com/articles/color-in-glass.shtml
dj
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Dance all you want, but keep one hand on the wheel.
Sometimes I swim, sometimes I sail, but mostly I just try to stay afloat.
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