Topic: Art glass vase - age & origin?

[uphoosier]

I suspect the decoration on this vase is to non-descript for an identification, but perhaps the unusual foot will suggest and age and maker to someone.  Thanks for looking.  It is 12" tall.

[uphoosier]

Darn you, Kristi!  About the time I had this figured for Bohemian, I read your comment in another thread. 
and the colorless Bohemian glass I have doesn't glow green

This one glows green.  Now what?

[krsilber]

Oh dear...maybe it's an exception, I dunno.  Actually, I think it looks kind of French.

[Ivo]

I would think this item originated in  North Bohemia or in adjacent Silesia. The yellow decoration may have been the enamel undercoat for gilding; often the gold has vanished leaving the undercoat in place. The green tinge comes from impurity (iron) in the used ingredients. Trying to get as colourless a glass as possible with those ingredients, glass makers used magnesium (a.k.a. glassmaker's soap) resulting in a very light green to very light amethyst. It tells you the glass composition was not the most sophisticated; larger factories would probably have used semicrystal which has no colour tinge.

[Lustrousstone]

Are you sure you mean magnesium Mg or do you mean manganese Mn Ivo?

[Ivo]

Darn, caught out. It's a fair cop, Guv!

[krsilber]

The green tinge is when it's lit with UV, right? 

Manganese when used in the right amount should result in a virtually colorless glass.  It would only have a green tinge if there's not enough to neutralize the iron, and purple only if there's too much put in or if it's changed over the years by sun or other UV source.  It was used in non-lead and leaded glasses alike.  Lead improves clarity and may act as a weak decolorant but usually something else was used in addition.  Of course, it's hard to generalize; I've only seen a few dozen of the thousands of old formulas for crystal and colorless glass, but that's what I gather from my reading.

[Ivo]

I'm not sure that brings a closer perspective on age, country of origin or glass composition.

[krsilber]

True!  There I go again, blab blab blab.  The glass composition stuff just fascinates me.

I think it's the boldness of the design, with its wide line and large scrolls that makes me think French rather than Bohemian.  That and the peculiar jagged design that looks like molars on the main scrolls.  Bohemian work generally seems more delicate to me.  I'm no expert on the subject, though, and bow to Ivo's broader knowledge.  Ivo, what kind of time frame are you thinking? 

Anyone have Bohemian glass that glows green, and if so, what date?

[Galle]

Wild speculation here... my impression of pieces like this one is that although the decoration at first glance appears to be Bohemian, these pieces are more likely English.

As I said, wild speculation on my part.