Topic: Faceted "Bohemian" opalescent paperweight

[rocco]

Something I haven't seen before: "Bohemian" flower-on-frit-ground paperweight, made of opalescent glass. (I have a soft spot for opalescent glass, so this was a must-have).
Gives a nice flower-in-the-mist effect, btw

Height 7 cm, diameter 8.5 cm.

I searched the web and the Brackel book for similar pieces, but even "normal" coloured casings seem rather uncommon with these weights.
So I guess impossible to find out the maker (date wise I would think 1920s/30s?), but I wanted to show it anyway.

Michael

[w8happiness]

Hi Michael,

an interesting material for a relatively common type of weights- here are some ideas:

based on the newly found Cryolithe mineral in Greenland, an opalizing glass was invented and taken for medicinal use, as artificial eye prothesis soon after 1885. From the Lauscha Glassworks, the material was soon a new standard, replacing the "milk" and "bone" glass that was used before. I have a good guess this could be the material the dome of your weight is made of...

I have not seen this material in paperweights, except for some splinters in Paul Ysart scrambled weights, probably in a test phase but rejected.
It looks like moonstone, with a blue and grey hue in side/top view, and yellow to olive looking through- maybe resulted from experiments for making smoky quartz artificially?

Please search "Daisuke Saito" or "Yoshinori Kondo" because modern Japanese marble artists are using "smoky" and "opal" borosilicate glasses, they are the present day successors to the old way...

But there are other influences not intended changing the colour of the dome as well- over times, enduring light exposure will darken or alter some glasses...   

What does it Show under UV LW/SW? Does it glow? Kind regards Erhard

[rocco]

Hi Erhard,
thank you very much for the detailed info!

Now having read a bit on the net about >> Cryolite glass, that certainly seems to be the material used in this paperweight.
(I still haven't quite understood if it is really the same as opalescent glass -- would that be distinguished depending on which additives are used?)
I think the glass itself doesn't have a colour (you may be right that the glass has darkened with age), all the colour effects appear when looking at the weight in different light situations -- quite fascinating. And the simple and not very well executed flower looks much more interesting in the mist

Maybe the paperweight comes from an area in Bohemia / Czechoslovakia where glass jewelery was made, like Gablonz -- they seem to have used opalescent glass frequently for beads.

Unfortunately, I don't have a UV lamp at hand atm, but will try to borrow one.

BTW, those Japanese artists produce some marvelous pieces...

Michael

[w8happiness]

...yes you are right, Gablonz with artificial Stones,
but also the old Swarovski dynasty- still strong with artificial gemstones!
Also Riedel who is still making top wine glasses,
 but had good colour glass experience as well.

"Compositions-Brenner"- mostly used for the makers of ruby glass- went on with
the search for new colours, decolorants, purifiers
and strengthening/modifying materials, it was a profession for specialists!

 Kind regards E.

[w8happiness]

Hi,

with  the formula Na3[AlF6) and the Fluoride content,
it surely will have a strong UV reaction,

cheers Erhard

[rocco]

Thanks for the additional info, greatly appreciated.
So the weight seems even more interestiing than I had thought initially

I will test it under UV and post the result...

Michael