Uranium glass, anyway-- it's still being produced by bead companies in the Czech Republic (and maybe other places as well, but that's been the main source of my uranium glass bead stash). Presumably the nastier isotopes have been depleted from the uranium before it goes into the vat.
The "why" is probably just "because it makes pretty colors"-- in this case, a light yellow or green that's mostly hidden by the blue glass it's blended with, at least until the UV light comes on. The yellow/green uranium color range tends to be subtly different from the relatively brownish yellows and aqua/emerald greens from other chromophores, though some types of uranium glass are nearly indistinguishable from similar non-uranium colors under normal viewing conditions. (I always have a small UV LED keychain with me to shine on possible candidates, which seems to mystify shopkeepers and other customers.)
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on 2010-05-13 08:32 pm (UTC)The "why" is probably just "because it makes pretty colors"-- in this case, a light yellow or green that's mostly hidden by the blue glass it's blended with, at least until the UV light comes on. The yellow/green uranium color range tends to be subtly different from the relatively brownish yellows and aqua/emerald greens from other chromophores, though some types of uranium glass are nearly indistinguishable from similar non-uranium colors under normal viewing conditions. (I always have a small UV LED keychain with me to shine on possible candidates, which seems to mystify shopkeepers and other customers.)