Topic: A question about glass that glows?

[selina]

After reading about uranium glass on a few sites and other glass that 'glows', I was wondering about a bowl I had. I was testing another item and I had a clear glass bowl next to it. The clear glass seemed to absorb the UV and glow white. Usually the clear glass reflects the purple UV back. This is an old art glass ashtray, nothing special but in all my collection its the only one Ive seen glow white. I even sat it next to another clear and coloured one to check I wasnt seeing things, but its definitely 'luminescent' I guess you could call it.

Its not uranium Im sure after reading because it says uranium glows green. So what is causing this bowl to glow? Im just curious to learn about this.

Thanks,

Trudy

[KevinH]

I can't say what makes your bowl glow "white".

However, the purple you mention as being "reflected back" is not UV light. Unlike some insects and birds, we humans cannot see UV light. The colours we see when using a UV light are "generated" by the interraction of the UV wavelengths with the atomic particles in the glass. Some UV light may be reflected back, but it is not visible to us. The reflected purple is from the fluorescent tube which glows that colour when in use.

[David E]

Glowing white is new to me - yellow for cadmium, pink/orange for selenium I am aware of.

Ivo's book expands this further to
Blue: leadglass and crystal
Yellow: soda

Kev – I believed that albinos' sight does border on the UV spectrum but I might be wrong about this. A friend (albino) used to have his monitor colours set up very strangely...

[selina]

Kev,

Sorry, error on my part, I meant it reflects the purple of the globe back.

Its definitely white to the eye but its really hard to get a pic. Thanks for your help though.

Trudy