Topic: Do I not understand? Lead in glass a barrier to fluorescence of uranium opaline?

[cagney]

  As the PK comment seems to lack a certain context, I guess we have just the facts as stated. I can'y imagine that the V&A QV bowl would be non-lead glass, as its mate in the CMOG is lead glass. The photo from V&A may lead you astray because of the lighting. Lighting can be important in regards to uranium lead glass. You may find this example interesting, if not illuminating.

   Pictured is an old timey real photograph c.1991. I took this photograph under incandescent light, no flash. I know for a fact that the pillar molded and cut vases in the photograph are the exact same vases pictured in this linkhttps://jeffreysevans.com/auction/pillar-molded-and-cut-pair-of-vases/ The presentation noticeably different?

[flying free]

ah, thank you!  I obviously didn't read the Corning information if it was on there.  Thanks so much.
Also yes the photographs. The Corning has one which is not lit iirc but it's still hard to discern what the colour is really like.  It's quite difficult to compare colour unless seeing comparisons in real life I think.
Thank you for that Cagney. So info so far on the V&A bowl - it's lead uranium glass, and apparently produced by Davenports at very short notice to supply for the Coronation banquet held at Guildhall in November 1837. 

[Ivo]

I think Siegmar may have meant to say that when you set out to colour a piece with uranium you better use standard glass. No need for lead crystal to bring out the colour. But I have a finger bowl from Baccarat around 1840 which is high quality crystal with uranium, turning it into Chrysoprase, an opaque opaline. I also have its companion, high quality dark green lead crystal. FWIW.

[taylog1]

This is a good description of why uranium glass fluoresce.
https://www.popularmechanics.com/science/a39995070/why-does-uranium-glass-glow/#
The UV causes an electron in the uranium atom to jump up a number of states (ie excited) as the electron drops back to its ground state (state by state) it can give off photons of lower energy.

And here are a few other materials that also cause glass to fluoresce.
https://libanswers.cmog.org/faq/143932
Different energy levels between the different states is why the colours vary by material.

[flying free]

Thank you Ivo   Would love to see your dark green uranium Baccarat finger bowl to make a comparison to my tumblers of same period.

Thank you Taylog

Interesting comment in that article in the link to Library CMOG (my bold - see quote below), in that I am pretty sure my old tumblers are lead glass and they're both green.  Have I misunderstood what I'm reading? 

'Leaving out the exotic elements not found in ordinary glasses, the responses are more-or-less as follows:

U (Uranium)-- A very strong bright-green response. The color of the glass itself in visible light is usually a bright yellow or yellowish-green, or an amber color in a lead matrix[/b]. ...'

[Ekimp]

Barrie Sketcher mentions lead glass weakening the uranium fluorescence from uv light. Page 3 para 3: https://www.glassassociation.org.uk/sites/default/files/Uranium_Glass_sample_article.pdf