Topic: Another question - is yellow glass particularly difficult to make?

[flying free]

I'm resurrecting this thread after many years it appears   It's still a question in my mind.

- I think I only have one more yellow piece (Non-uranium) than I had when I posted this originally- a satin glass vase fairly opaque, with clear satin glass handles - no idea where from.  Looks like it could be LaFiori but I really don't know. 
So five pieces in total.  But it's a question that continues to vex me every so often - why is transparent yellow glass so difficult to find.  True yellow, not coloured with uranium.

(In a similar vein, I also raised a question on a different thread about why red or ruby glass never seemed to appear in the spectrum of Sklo-Union glass.  And yellow is another of those colours I think.  Amber is there, yellow doesn't seem to be from memory.)

- Having re-decorated a room with a bright yellow velvet chair I find I'm dependent on my one yellow Schaumglas piece (from Loetz? or WMF?) for my display.  I have the yellow Carlo Moretti satinato but that's elsewhere with the whole set. And I have one Aseda yellow vase, again needed elsewhere.

- The only other piece I have is what I think is an Empoli shape. 
It's a very large piece, a very good transparent bright yellow glass.  Quite similar to the yellow of the Schaumglas vase actually .  It's just a clear transparent yellow.


-Tonight out of curiosity I got it down from storage and checked it again with a blacklight and it  glows with an immediate and fluorescent vivid bright orange - so I assume is coloured with Cadmium? 

The Schaumglas vase does not glow orange, in fact it doesn't glow at all.  The Aseda and the Moretti vases both glow  a strong green but it doesn't quite look like a U green fluorescent green and they don't look like Uranium yellow glass in daylight either. They are also a bright yellow glass.  The Moretti is opaline satinato.  The Aseda is not really transparent like the 'Empoli' vase - difficult to explain.

- So, I was doing a bit of reading this evening and came across this information from 1895.  It appears to be dated 15th March 1895 although I know from previous reading of these types of documentation that information can sometimes have originated from a much earlier date and  just copied from year to year so it could be from earlier.  In the particular section I mention it states at the end 'Specially translated from Diamant for the American Manufacturer .  I have no idea what Diamant was.

See page 374 of the American Manufacturer and Iron World Pittsburgh 1895.
Under the heading 'American Manufacture.  Glass.  Yellow glass' :

The author discusses using silver chlorides to colour glass yellow.  It says it is chiefly used for 'flashed work' and 'cannot be used for alkali-lime glass' and 'consequently used to colour the more fusible lead glass'.
Then the use of silver chromates.
Then the use of uranium and under uranium also mentions that a large quantity is necessary and it's very expensive and so was only used for the finest grade glass. 
It then goes on to say:  'The latest material to come into use for coloring glass yellow is cadmium and it's compounds.'  (See middle column for detailed information.) 
From my reading it seems that not only was sulphide of cadmium  difficult to use in the making,  it also caused problems in the annealing process?

https://www.google.co.uk/books/edition/Steel_and_Iron/j7E4AQAAMAAJ?hl=en&gbpv=1&dq=cadmium+in+yellow+glass&pg=PA374&printsec=frontcover



To summarise ( and open to correction as I have no idea about glass chemistry and making )
It reads to me that uranium was expensive and could only be used in fine glass, cadmium could be difficult to control in the making and the annealing, and silver could not be used for alkali-lime glass and only for the more fusible lead glass. 
Therefore I wonder if that's why it's still quite hard to find a good transparent yellow glass?  Not amber.  Not uranium yellow.  Not cased or opaline.  But a good clear transparent bright yellow glass?

m



 

[Anne]

Your post made me wonder about the availability of yellow glass, M,  so I resorted to a Google image search to see what comes up, and a fair bit does, but I have no idea if they contain uranium or not, of course. :'(  I do have a paperweight containing a yellow flower design but very little else in yellow except my Heron Glass bowl which is yellow but isn't clear glass.

Some examples to explore in the meanwhile:  https://www.pinterest.co.uk/theglassgarden/yellow-glass/
and this gorgeous yellow bird!  https://www.etsy.com/uk/listing/551340930/yellow-glass-bird-ornament

[rocco]

This is an interesting thread.

I cannot contribute to the chemical side; so if it is a matter of technical difficulties or taste why we see yellow glass less frequently I don't know...
So just some random thoughts

I think that one aspect is that, yellow being a light colour, we don't perceive transparent yellow as a strong colour.

To get a really strong yellow, there is usually some sort of opaqueness to the glass (opaque yellow, yellow over white, opalescent yellow).

I looked through my collection, and attach a few pics:

1. Sklo Union pieces do come in yellow, though it is not a really strong one

2. Citrin pieses like this one from Hessenglas or pieces from ZBS (or Moser a few decades earlier) are surely a clear (yet light) yellow

3. Aseda goblet (@m: I totally forgot about this one ) shows really strong yellow due to opalescence I think, but is not transparent.

4. The only true strong yet totally transparent yellow in my collection is this Murano bowl. As far as I remember it is not Uranium glass

Karcag also had a strong yellow. I think again due to the reflectiveness in the glass (from the fine crackle) >> Link

Michael

[flying free]

I have that Sklo Union bowl - not really yellow  in my eyes  - I would class it as Citrine although I know it appears darker than the vase below it in your post.  It's a gorgeous colour but not quite the same.

I also have a little triangular bowl that I had in dark green, proper yellow and also a turquoise. I thought they were Sklo Union pieces originally but I think they were determined to be Polish in the end.  ... hang on just going to check the glow on the small bowl. Ooh have just checked the triangular bowl and it glows bright orange as well!   hmm. I'm wondering where my 'Empoli' shaped vase was made. I say 'Empoli' shaped because it reminds me a little of this pink one
https://www.glassmessages.com/index.php?action=dlattach;topic=38356.0;attach=64773;image

I will try and get a good photograph and upload. 


Edited to add:

Ok, I've had to squash them together to get a representative light through them from the winter light outside.
The amber one is a Sklo Union vase on the left, the 'citrine' bowl on the right is also Sklo Union. Neither glow orange under blacklight.
The 'Empoli' shaped vase and the little triangular bowl are the same colour and both glow orange - maybe from the same maker?

Anyone seen anything in the shape of the big yellow vase then?
m

[flying free]

I think I was wrong about the triangular bowl - can't see anywhere on the board where it has been id'd.

[English weather]

John Walsh Walsh Primrose seems pretty yellow to me

https://fieldingsauctioneers.co.uk/lot/175015

I believe the bright yellow is obtained by casing white opaline with amber. It was certainly the case with a Victorian lily vase I had which was bright yellow though at the very base of the trumpet which had no casing, you could see it was amber. That particular vase was made by Kempton.

[chopin-liszt]

Flying-free - could your Schaumglas "query" vase be WMF Medusa?
I had a piece and discovered that was the name for the yellow incarnation. It is quite an unusual range. I'm pretty sure it glowed bright orange in uv.

[flying free]

Hi Sue - thank you I queried it because I've never been quite sure whether it was Loetz Schaumglas or WMF Medusa.

Mine doesn't glow  - nothing at all under blacklight. Lead glass and not coloured with cadmium then maybe? Perfectly polished pontil mark in the middle.  The white internal decor is white powdery stuff not bubbles and was gathered on the first gather (very bumpy on the internal wall of the vase) and then finely cased over on the external layer also of yellow glass.  It looks very yellow.

[flying free]

Thank you Anne for the images They've prompted me to do some more searching.


English Weather thank you .  That's interesting how Walsh Walsh have created their yellow.  The link I gave discusses also how silver was used to colour over opaque white glass I think.  Fascinating how they've all developed their own methods of creating the yellow appearance.


I've been on a mission and found some Welz yellow coloured with cadmium.  Great colour!  Welz also patented an orange as well.  They were the teenagers of glass of their time in my eyes - way ahead of their time in developing amazing fabulous decors and great shapes.  I think of them as the Harvey Nichols to Loetz's Harrods 

http://www.kralik-glass.com/welz-images/draped/wdraped4.jpg

[flying free]

I also have a little triangular bowl that I had in dark green, proper yellow and also a turquoise. I thought they were Sklo Union pieces originally but I think they were determined to be Polish in the end.  ... hang on just going to check the glow on the small bowl. Ooh have just checked the triangular bowl and it glows bright orange as well!   hmm. I'm wondering where my 'Empoli' shaped vase was made. I say 'Empoli' shaped because it reminds me a little of this pink one
https://www.glassmessages.com/index.php?action=dlattach;topic=38356.0;attach=64773;image

and


The 'Empoli' shaped vase and the little triangular bowl are the same colour and both glow orange - maybe from the same maker?

Anyone seen anything in the shape of the big yellow vase then?
m

I've just remembered that I think the little yellow bowl and it's blue and green counterpart were I think made by Jablonecke Sklarny ?
Just checked online and all I can find is a set of these little ashtrays that look similar by Vaclav Hanus for Jablonecke Sklarny apparently.  Mine are not ashtrays (no indents, just a really well designed counter wave rim).
https://www.worthpoint.com/worthopedia/vintage-set-bohemia-colored-glass-17341277

So that's possibly where the little triangular bowl comes from but I don't really think the vase was from there.  It's mold blown and has a slightly pattern base from the mold design.