Topic: Glass vase with applied trails/feet; Harrach or S&W? Other?

[krsilber]

If it's the same kind of glow you find in colorless glass, then Christine's right, it probably isn't uranium.  If you can see that in blue or green glass, it makes me wonder how many people out there think their green glass contains uranium when really it's something else glowing.

[Galle]

Here we go... best I could do... First pic is the green leg, second pic is the blue one, third pic kind of shows both green and blue legs and the amber glass in between.

[Lustrousstone]

That's the manganese glow.

Kristi, lots of them. I see it on ebay and online shops all the time and nearly as many of them know it's got uranium in when they admit they haven't got a black light! When you collect uranium glass you get an eye for it in photos, not an infallible one I admit but...

[Galle]

Good discussion - one more question and I'm done... does the use of manganese in a piece like this one give any additional clues to its origin? I still think Harrach is the more likely player, but I'm now wondering if it there is a chance this could be a French piece.

[Ivo]

The answer is no, glass composition in itself does not point at a region or country of origin. Only if you have two glasses, one of known and one of unknown origin with the same characteristics can you draw the careful conclusion that these might be related. Possible makers for this piece will include Sevres, Meisenthal, Valerysthal, Pantin, Clichy, Legras and Auguste Jean  - apart from the usual Bohemian suspects.

[Galle]

Thanks, everyone.  :thup:

[krsilber]

As some of you know, glass composition and glass fluorescence are particular interests of mine.  So if I tend to ramble on about them and ask lot of questions, that's why.   

I'm sure there's a lot of green glass on ebay that is said to be uranium glass but isn't.  Still, I think a lot of it one wouldn't expect to contain U based on the photos (I wouldn't, anyway).  I was just reading some old threads in another forum, chataboutdg.com, about green fluorescent Depression glass.  Unfortunately, you have to be registered to see them, but here are the threads for those who are registered or would like to.  It's an excellent board if you have anything you suspect is American Elegant or Depression.
http://chataboutdg.com/invision/index.php?showtopic=8290
http://chataboutdg.com/invision/index.php?showtopic=8124
http://chataboutdg.com/invision/index.php?showtopic=8366

Mod: links no longer work after website reorganisation.

There's a married couple there who collect transparent green Depression glass and they're quite interested in the causes of fluorescence.  Much of their glass contains uranium.  I'm not a collector of uranium glass, and don't have the eye for it that others would, but FWIW some of it I wouldn't have pegged as uranium.  A couple pieces I used to own are shown below, a Tiffin center handled server and a Cambridge bowl.  Both looked pretty normal (to my eye) under most light, though they'd glow a bit at dusk.

Cambridge's Willow Blue also had uranium in the formula:

The green glass collectors have a shortwave UV light as well as a longwave.  They showed a couple photos of a sugar and creamer set that glowed bright green in LW UV, but in shortwave, one glowed green and one glowed bright blue!  A good example of glass formulas changing over the years.

This is irrelevant, but neodymium is used as a decolorant sometimes, and is supposed to fluoresce in LWUV.  Does anyone know what color?

Concerning different glass compositions in different regions, Gary Baldwin in Moser Artistic Glass reportedly used the combination of shortwave and longwave UV to discern among 3 glass types:  Bohemian potash-lime, Venetian soda-lime, and European lead crystal.  Apparently most Bohemian non-lead glass formulas from about 1850-1930 were based on one by Meyr's Neffe.   Although he seemed to be aware that you have to be careful with your testing, it's hard to know what range of glass he used, and how many replicates.  It would be nice to know if his results were reproducible.

Incidentally, he also found a gradual change in the shortwave fluorescence color of Moser through the 20th C...makes one wonder about the use it might have in dating if something like that could be properly documented.


Mod: Links to clicksnipwow removed as site is no longer connected to glass. Please visit http://chataboutdg.com/forums/ and use the search function instead

[Lustrousstone]

The edge shots are generally the giveaway for green uranium glass - can't tell from yours

[krsilber]

I guess that's an indication that it's sometimes hard to tell in things like ebay listings.  Here are a couple shots of another Cambridge piece, two different backgrounds.  It seems like there's kind of a nondescript glow in the edge of it, and also when you look at the edges of the stack of Willow Blue Cambridge plates in the second photo.  But that could just as easily be due to the light and other colorants.  Did you see the Willow Blue collection?

(These photos are from my early days of glass photography!)

[Lustrousstone]

Yes that's what I mean, it's a sort of hazy glow rather than a sparkle. Not convinced by the Blue Willow at all, I would expect a tiny hint of a green glow