Topic: Asymmetric, white-flecked, green glass obelisk - 188mm tall - no markings

[Ivo]

Mexican quartz glass is another possibility.  They use panel cutting to high standards. But I must admit, I have never seen any with inclusions.

[Repz]

I picked it up for a nominal fee on eBay a year or two ago - basically just paid postage.

[rosieposie]

A gemologist should be able to use a spectrometer to tell you if this is glass or a cut gemstone.  It does look very much like glass to me,  but many semi precious gemstones have been carved and sold on eBay as glass, and vice versa.

[Repz]

A gemologist should be able to use a spectrometer to tell you if this is glass or a cut gemstone.  It does look very much like glass to me,  but many semi precious gemstones have been carved and sold on eBay as glass, and vice versa.

This all sounds very expensive...

Seriously, I would really like to know exactly what it is or roughly what it is and what the inclusions are. I don't care about what it's worth - particularly - I just have an enquiring mind.

[Repz]

I'm - I was - a chemist.

[pamela]

With its bubbles inside I would definitely rule out precious or semi-precious stone. As a chemist, you certainly have considered and ruled out any resin material? 

[rosieposie]

Not expensive at all Repz.... if you go into a decent Jewellers and ask them to run it by their spectrometer, they should take it into the back of the shop and put it under the spectro for you.  I bought a box of 'stones' at a bootfair because there was a piece that looked like yellow glass and I took it into our local (Surrey at the time) jewellers and they put it through their spectro and declared it was gem quality Citrine, I seem to remember they simply asked me to put a donation into the Barnardoes collection box they had on the counter.

However if you can definately see air bubbles in it,  then you have already ruled out natural stone and this does sound like glass.

Hello Pamela, looks like our messages crossed in the airwaves.

[Paul S.]

bearing in mind comments about nominal fee cost, is it worth considering that this is simply some ultra cheap type of bottle glass with masses of inclusions which are usually described as 'seeds or stones' and quite often this whitish/grey colour.               Such low grade glass is frequently this greenish colour owing to the iron impurities in the sand and with non-silica debris that doesn't melt at the same temp. as the sand.            This 'bottle' type glass would probably also be more inclined to contain bubbles than refined glass.         Just a thought.
Might see if you can scratch your name on a window pane to test the hardness of this material  -  quartz should be 7 on the Mohs scale, I think.

Of course if you really want to determine the nature of the inclusions then break the obelisk and take some of the whitish 'crumbs' to another chemist.    

 

[Repz]

bearing in mind comments about nominal fee cost, is it worth considering that this is simply some ultra cheap type of bottle glass with masses of inclusions which are usually described as 'seeds or stones' and quite often this whitish/grey colour.               Such low grade glass is frequently this greenish colour owing to the iron impurities in the sand and with non-silica debris that doesn't melt at the same temp. as the sand.            This 'bottle' type glass would probably also be more inclined to contain bubbles than refined glass.         Just a thought.
Might see if you can scratch your name on a window pane to test the hardness of this material  -  quartz should be 7 on the Mohs scale, I think.

Of course if you really want to determine the nature of the inclusions then break the obelisk and take some of the whitish 'crumbs' to another chemist.

Thanks. That seems pretty convincing. I worked as an organic chemist for Big Pharma so this is not my area, as such.

[Repz]

many pressed glass surfaces appear shiny and polished, and was this ability to mimic cut glass that brought into being much of the trade in pressed glass in the middle of the C19 - although the sharp 'edges' of true cut glass probably always defeated the makers of moulded work.
The sharp edges of cut glass were lost after the 1920's as a result of acid polishing which was a more economical and rapid method of removing grinding marks.            Run your fingers over a piece of mid C20 cut glass and the smoothness is very apparent, usually.

The intersection of two flat surfaces - form an arris - or edge as you say, and on older glass these raised features are vulnerable to damage although far less so the newer the piece.

If you can get alight source to provide a raking effect on the sides, and get your eyes really close (or use a loupe) you should be able to assess whether this is pressed or cut.
If cut, then you should see, albeit faintly, the shadowy remains of grinding marks  -  the merest hint of lines running at ninety degrees to the axis of the obelisk  -  if pressed then no matter how close you look you will never find even a hint of these lines.

If the inclusions are mica, then under a decent light individually they should give a hint of sparkle, especially as mica flecks usually show flat planes  -  according to Wiki the word mica is derived from the Latin word, mica, meaning a crumb, and probably influenced by micare, to glitter.
If the inclusions are a dull white, then not really sure what they'd be  -  sorry.

Now off for more chocolates, beer and tv.    merry Christmas all. 

Thanks, I now know my arris from my elbow. As an update, I have lost the blasted thing now, but if and when I find it, I'll take it to a jewellers for them to zap so they can tell me what exactly it is. Hope you enjoyed your beer and chocolates. And a belated HNY to everyone else who contributed to this thread.