willong
Well-Known Member
Had sandchip not beat me to the punch explaining the amethyst colorization, I was going to lead off with a mysterious question for Catcat16: Where are you living, young lady, that gets such intense sun?
I grew up on the fringe of the Mojave. Before everything got picked up and carted away, sun colored glass was fairly common lying about the desert. Even given that combination of intense sun exposure and a dearth of accumulated organic debris to cover over discarded glass, one rarely encountered bottles so evenly and deeply colored.
To sandchip's excellent summary, I'd like to add that the World War One era glass de-colorized via addition of selenium will also colorize with exposure to ultraviolet light. However, in that case, the change results in a light yellow or straw color--so I have read. Which begs the question: with light amber being a fairly common glass color for a number of products in the early twentieth century, how does one determine if a bottle they have found in such a color from the correct timeframe was thus originally produced, or turned a straw color due to UV exposure?
Could any member here post pictures of selenium glass confirmed to be sun colored? If so, unless the color is so unique to make it obvious, please explain how you know.
One other tidbit: I've read that reheating sun colored glass in an oven, even without remelting, will revert it to clear colorless condition.
I grew up on the fringe of the Mojave. Before everything got picked up and carted away, sun colored glass was fairly common lying about the desert. Even given that combination of intense sun exposure and a dearth of accumulated organic debris to cover over discarded glass, one rarely encountered bottles so evenly and deeply colored.
To sandchip's excellent summary, I'd like to add that the World War One era glass de-colorized via addition of selenium will also colorize with exposure to ultraviolet light. However, in that case, the change results in a light yellow or straw color--so I have read. Which begs the question: with light amber being a fairly common glass color for a number of products in the early twentieth century, how does one determine if a bottle they have found in such a color from the correct timeframe was thus originally produced, or turned a straw color due to UV exposure?
Could any member here post pictures of selenium glass confirmed to be sun colored? If so, unless the color is so unique to make it obvious, please explain how you know.
One other tidbit: I've read that reheating sun colored glass in an oven, even without remelting, will revert it to clear colorless condition.
