Topic: Not all uranium glass reacts to UV

[Frank]

http://www.orau.org/ptp/collection/consumer%20products/vaseline.htm

Unfortunately they don't say why.

[Ivo]

http://news.softpedia.com/news/Uranium-Responsable-for-Precious-Opal-71729.shtml

seems uranium is used as a marker, so the info could be of dubious quality.

[Frank]

Intriguing that by weight, up to 25% has been used in vaseline glass!

The rest of the site is interesting too, quite surprising how many everyday items are radioactive.
http://www.orau.com/ptp/museumdirectory.htm

[Ohio]

Oak Ridge Associated Universities...as in Oak Ridge Tennessee, AKA Atomic City, home base for the Manhattan Project's  Uranium-separating facility for the atom bomb.

[krsilber]

http://www.orau.org/ptp/collection/consumer%20products/vaseline.htm

Unfortunately they don't say why.

My guess is that some other constituent is a powerful absorber of UV or of the wavelengths emitted by uranium as it fluoresces.  Just a guess!

Interesting article!  "Purists might argue that the green sugar bowl in the picture should not be considered Vaseline glass because an additional colorant (probably iron) has been used in addition to the uranium to produce the green."  This implies that true vaseline owes all of its color to uranium, and glass with any other colorant shouldn't be termed "vaseline."  I never thought of it that way or heard that as a way to limit the definition.

[Lustrousstone]

That is the way that many US (and possibly other) vaseline glass collectors view it and they won't consider anything but yellow. The name comes from the fact that Vaseline, as in the greasy stuff, was originally much more yellow than it is today because it was much less refined and not bleached in any way (I seem to remember it so from my childhood). It's shiny translucent qualities provided yet another similarity. Me, I'm not fussy as long as it has uranium in it...

[Ivo]

it has always been my understanding that true vaseline glass has zinc in it so it strikes to a milky semiopaque at the edges when reheated and then resembles petroleum jelly. This material was extensively used in victorian table ornaments (I believe Leni has an awsome collection of these "thorn vases" in vaseline glass).

I would never use the word vaseline to describe a straightforward uranium coloured item. To me, vayzeleen is an americanism, an ugly misnomer which was introduced very recently. I'll stick to British usage.

[Frank]

That probably explains why I am confused by the term vaseline! In my more active days 1980's I was sure it was used for something else in glass and only really came across it in Uranium context in the last ten years. But, as I do not clearly recall what was called vaseline 30 years ago, I am not much use in this debate.

[krsilber]

"Vaseline" may be an American term (we say "vassileen"), but it is by no means recent.  This is from a post of mine in another thread:

Wow, I actually found a credible reference for an early date of the term!  I'm astonished.  A quote from this site: http://www.go-star.com/antiquing/vaseline_glass.htm
"There was also a new petroleum ointment on the market during this time period called vaseline, and the formula for the jelly at that time was the same color as this soda-lime formula of yellow glass, so coincidentally, people started calling the yellow glass vaseline glass. The oldest reference I have found in print is from N. Hudson Moore's book, Old Glass: European and American (c. 1924). On page 349, she writes, 'All the pieces shown in figure 207 are in this royal purple and canary yellow, which, by the way, no real collector would ever call vaseline, a dealer's term.' "

Seems there were objections to it even then!

Another quotation from the same site, the definition of vaseline according to "the only worldwide collectors club for this glass, The Vaseline Glass Collectors, Inc.," doesn't mention anything about zinc, nor does it say that uranium can be the only colorant:

"'Vaseline glass is a transparent, yellow-green glass that will fluoresce a bright green color when exposed to any ultraviolet light source, due to the addition of a 1%-2% amount of uranium dioxide in the original glass formula. The transparent quality may be obscured by treatments such as opalescent, carnival, iridizing, stretch, satinizing, sand or acid etching, casing, inclusion and cutting treatments. Hand painted and applied decorations are also acceptable. These treatments do not change the original transparent quality of the glass. The name vaseline glass is due to the similarity of the color to that of petroleum jelly as it appeared in 1901.'"

Is there a British equivalent for the term besides "yellow uranium glass"? 

Intriguing that by weight, up to 25% has been used in vaseline glass!

That is odd!

[Frank]

I think Ivo hit it on the head, the stuff with zinc is without uranium. Lots by Powell and others late victorian period. So the US variation was introduced by dealers and ultimately has stuck. Misnomer or not, it has become common parlance and visitors here caught the bug too.