Glass Message Board

Glass Identification - Post here for all ID requests => Glass => Topic started by: mc3378 on February 27, 2012, 05:47:44 PM

Title: Help with maker of green bowl with aventurine
Post by: mc3378 on February 27, 2012, 05:47:44 PM
Hoping someone has an idea about who made this bowl. It is 12 1/2 by 11 1/2 inches and glows under a black light. I would be thankful for any help.
Title: Re: Help with maker of green bowl with aventurine
Post by: Paul S. on February 27, 2012, 11:19:16 PM
sorry, can't help remotely with any kind of attribution, but just wanted to ask if you are able to post a picture of what you're saying is a uranium glow.     Didn't  really want to show my ignorance but wondered if by any remote chance this piece contained aventurine/metalic flakes - which might have been responsible for the glow :)
Title: Re: Help with maker of green bowl with aventurine
Post by: Paul S. on February 27, 2012, 11:20:57 PM
apologies, it's late, and I'm not reading everthing properly :pb:    Still appreciate the extra picture if possible. :)
Title: Re: Help with maker of green bowl with aventurine
Post by: mc3378 on February 28, 2012, 04:50:37 AM
I have a cabinet full of uranium glass and this piece doesn't light up like those do, but it does glow a light green and more on the edges of the bowl. I'll try later to take a picture.
Title: Re: Help with maker of green bowl with aventurine
Post by: Lustrousstone on February 28, 2012, 07:35:52 AM
The light green glow is just the manganese decoloriser and, in this case, probaly indicates older (50s/60s/70s) rather than new glass.
Title: Re: Help with maker of green bowl with aventurine
Post by: mc3378 on February 28, 2012, 05:03:21 PM
Thanks for your input and I agree it is the manganese that causes the glow. My question now is,  does that make it a poor quality of glass because of the glow? Also does anyone think this could be murano glass. Thanks for any information you can give me.
Title: Re: Help with maker of green bowl with aventurine
Post by: chopin-liszt on February 28, 2012, 05:28:16 PM
I'm not sure, but Lustrousstone's comment leaves me sure that it's unlikely to be contemporary Chinese, which was my first, but unsure thought. (so I didn't mention it  :angel: )
Title: Re: Help with maker of green bowl with aventurine
Post by: Lustrousstone on February 28, 2012, 07:36:42 PM
Decoloriser is used in most glass because unless you have access to very pure white sand (like that from Loch Aline), you don't get colourless glass. Manganese is rarely used these days because it got too expensive; it's a heavy metal; and it goes purple in sunlight.

I don't know whether it's Murano or not. Perhaps Czech?
Title: Re: Help with maker of green bowl with aventurine
Post by: mc3378 on February 28, 2012, 08:43:31 PM
Thanks for the education. I was wondering murano because there is one on ebay like mine only a different shape and they claim it is murano, but I don't trust everything I read there as being true. I myself was thinking either Czech or Polish. I don't see any purple when I hold it up to sunlight. Thanks again for the great information.
Title: Re: Help with maker of green bowl with aventurine
Post by: Lustrousstone on February 28, 2012, 08:46:25 PM
No you won't see any purpling. Look up sun purpling and you'll understand what I'm talking about. It's a long-term chemical reaction often seen in old clear glass.
Title: Re: Help with maker of green bowl with aventurine
Post by: mc3378 on February 28, 2012, 08:59:13 PM
Thanks, I think I know what you are talking about I have a few really old I think champagne glasses that outside has purple but also glow a light green under the black light. It's great the things you can learn on the internet.