Topic: Wine glass with odd touch of opalescence ?

[keith]

4.5 inches tall, marks to the foot, top and bottom, what causes the opalescence ? 

[chopin-liszt]

  Perhaps some random inclusion of potash?

[Ekimp]

So it isn’t just the water staining/damage on the inside surface? Looks like a proper deception glass with thick walls

[Paul S.]

Hi Keith  -  are you sure this isn't a case of 'bloom' on the surface of the glass - rather than true opalescence?     Apparently soda-line glass is susceptible to blooming - something to do with build up of crystals on the surface of the glass.
What age are you suggesting for this piece - it may have some bearing on the breakdown of the surface of the glass  -  you might try an abrasive or polishing compound on part of the affected area and see if there's any change.
The mark on the foot looks like the 'T' mark from the shears  -  you might fill with wine so we can see the capacity of the bowl

[chopin-liszt]

It looks like water staining a little in the first pic - more like a true opalesence in the second pic.
What does it truly look like?

[keith]

No idea if it's potash Sue, doesn't look like any water staining I've seen before, the capacity is quite small but the glass is chunky round the base but nothing like the deception glasses I have, the 'bloom' or whatever it is can only be seen in very strong light. Quite heavy for it's size, plenty of wear, maybe late Victorian, Edwardian ? ( wish I'd never started collecting drinking glasses ! ) 

[chopin-liszt]

You can feel water staining. It's not all smooth and shiney. I imagine bloom on a surface would also feel different. 

[keith]

Definitely not water staining, seen lots of that, can't feel anything. oh well only cost £3 and it looks good with the others so I'm happy 

[keith]

Clear as a bell in normal daylight 

[chopin-liszt]

It must be in the glass, whatever it is - and only very faintly. Opalesence does require the light at the correct angle to show up, especially if it's very diluted.
It is sounding like an accidental potash inclusion, to me.

Is potash something likely to be flying around occassionally in an old glassworks?