Topic: Rubina Verde bowl.

[Paul S.]

Thanks to Lustrousstone's recent comments on my small stick http://www.glassmessages.com/index.php/topic,35990.msg195552.html#msg195552
- immediately I saw this bowl in the flea market, I knew what it was.   About 3.5"/85mm tall  - optically moulded, and with the rim ground and bevelled.   This is only the second piece I have been aware of seeing - so it certainly does appear uncommon.   Notice how the cranberry colour is so very unequal in its coverage of the bowl.
If by any extremely remote chance anyone considers they know what the piece is, or maybe a maker, I would like to hear.   Otherwise, hope you enjoy the view, and thanks for looking.

[chopin-liszt]

Is it not a "double-strike" method used to get the colour change?

(a secondary heating to a particular temperature will change the colour chemistry)

[Paul S.]

Whether the method of producing this effect was difficult or whatever, I know not Sue, but it remains a fact that in comparison with ordinary U. glass, rubina verde appears very uncommon.   Maybe there was a high failure rate when 'striking'.    I can say for a fact that U. is present equally throughout the entire bowl shape, although when viewed in daylight the 'red' masks the green in the upper portions of the bowl- although with the uv torch the 'green' can be seen, although not as clearly as in the base.    One of my books, when speaking of glass containing Uranium, says........"In a very high lead-containing glass (with 71% lead oxide), it gives a deep red colour"   -  unfortunately, the book doesn't comment that the piece needs striking to bring out the red, but that action would be a strong possibility.    Since reading those comments, I have given the bowl a flick, and it has quite a striking 'ring', so some lead content a strong possibility.   So, maybe answer is ....add lead oxide to the uranium glass, strike (or re-strike) and lo and behold you have 'rubina verde'.     As an ex lab. chemist, what do you think? 
Reference:   The Encyclopedia of Glass  -  Edited by Phoebe Phillips  -  1981 (page 258)   -  Incidentally, a useful book.

[chopin-liszt]

I only do organic stuff Paul. Biochemistry/pharmacology.
Not the hard stuff for me - just the horribly complicated.

[Paul S.]

Couldn't remember there being any rubina verde in either of the Barry Skelcher books (on Uranium Glass) - but good job that I looked  -  as there is a candlestick in one and a comport in the other - although the red is more of a faded pink.      I'd obviously missed seeing them.  Skelcher doesn't index these as rubina verde, both pieces are pressed, and he does actually comment that..........."I suspect the press mould was loaded with two separate gathers" .........and this is borne out by the fact that my stick has the two colours separated properly, and without any glow from the pink.      It is an extreme coincidence that the stick shown in Skelcher's book is identical to mine!      I should look more carefully at the pictures in books.     Skelcher considered that both of his pieces were from the same origin, but no idea where.
I'm thinking that neither the stick nor the comport (being pressed) will have contained any lead, so reheating would not produce the effect as in this bowl, therefore the process is entirely different, and the end product equally disimilar. 
Perhaps we should now create separate descriptions for these different products     Any offers.
See here for the candlestick.......http://www.glassmessages.com/index.php/topic,35990.msg195517.html#msg195517

Sue...Oh, but I'm sure you are very good at it.

[Lustrousstone]

I think there are two ways of making rubina verde. The Hobbs-Brockunier rubina verde was apparently heat struck. Your bowl I suspect was made by blowing a small gather of cranberry into a larger bubble of vaseline until the cranberry bubble burst, which would explain the uneveness. Heat striking is usually more even because the pontil holding the item is rotated in the furnace. See http://www.vaselineglass.org/blacklight.html for what Dave has to say.

Rubina verde (ruby green) is a colour scheme rather than a technique. There is also the scarcer rubina blu. I have some rubina verde beads and they definitely weren't heat struck.

[Paul S.]

thank you Christine  -  do you know where I might see a picture of rubina blu.?

[mrvaselineglass]

Rubina Verde was a trade name coined by HOBBS, BROCKUNIER, & CO., and it has become a generic term.  It is a process and a color.  It is not 'heat struck' glass, like burmese or amberina.  A small gather of cranberry glass is put on the pipe.  A larger gather of vaseline glass is then put over the top of the cranberry.  It is blown into a mold, and the cranberry does not expand as far down the mold as does the vaseline.  If you notice in the cup (top of page) under the UV blacklight, the green shows up all the way to the top.  That is because the gather of vaseline/uranium glass completely covers the cranberry gather.  Under normal light, the red is darker, so it is not seen (or not seen very easily) until you put the UV light on it.  While rubina verde is scarce, rubina verde opalescent is even tougher to find.  That included putting additional ingredients into the vaseline/uranium metal so that when the glass was heated in the glory hole, the piece 'struck' the opalescent on the vaseline.  The cranberry is not affected by striking the piece in the glory hole.

Here is a good example of a piece of rubina verde opalescent.  the main shape was made, the piece was struck to get the opalescent effect, then the top was crimped and shaped.  Next, the glass worker added the wavy pattern mid-bowl, then added the base with the pinched feet.  The piece was either not returned to the glory hole, or, the vaseline glass trim was not of the opalescent variety.  That would mean they would have had to have a separate pot of just regular vaseline glass.  This marmalade dish is 6 3/8" across the top rim.  I don't know the maker.  The blacklight photo gives an easy way to see the two separate layers of cranberry and vaseline opalescent, especially at the top rim.  Also notice, that with the blacklight, you can see the glow coming through the top of the bowl, so the cranberry on this piece is very thin (and I have a strong blacklight).

This glass method was used by Hobbs, Brockunier & Co.  It was also used in Bohemia, and in England.  I find that the red fades gradually on the pieces from England and Bohemia, where the stuff from Hobbs has a sudden ending point. 

The rubina blue uses a small gather of cranberry, with a layer of blue over the cranberry.  I have seen pictures of red tops, blue bottoms on some Hobbs tumblers.  The blue goes all the way up the outside of the tumblers, and just has a cranberry inner rim, that usually goes about 1/3rd down on the inside. 

Pieces with red at the bottom and the other color at the top are just stained glass.  it is not rubina verde unless the red is on the inside and at the top where the piece was removed from the pipe.

http://www.vaselineglass.org/marmaladefooteduv.jpg

here is a picture of a Hobbs Rubina Verde Hobnail tumbler, next to a vaseline opalescent tumbler (also by Hobbs).  Notice on the RV piece that you can see the yellow around the outer points of the area in red.  that is the outer layer of vaseline.

http://www.vaselineglass.org/rubina.jpg

Another Hobbs piece, this time an 8" bowl with attached vaseline feet.  The vaseline completely covers the outside of the bowl.
http://www.vaselineglass.org/hobbsrvpd1.jpg

And this one is my pride and joy: a 5" fitter shade in rubina verde opalescent by Hobbs, Brockunier & Co.  I like the center photo the best, as morning light came in and the sunlight lit up the uranium glass.  Notice how the green goes all the way up to the top of the rim on the left side?  The photo on the right has the blacklight coming from the inside, and the thicker the cranberry, the more the UV is blocked.  the UV shows some at the lower points on that one, but the sunlight lit it all the way to the top.

http://www.vaselineglass.org/hobbs17063.jpg

these pieces use the same method as rubina verde, but has an opaque pink for the inner gather instead of cranberry.
http://www.vaselineglass.org/peacockposeybl1.jpg
http://www.vaselineglass.org/peacockvasebl1.jpg

As far as the original poster and the little cup.  the uranium glass is kinda on the green side.  If it was yellow on the base, I would have suggested it was Phoenix Glass as the maker.  This might be continental Europe. (just a wild A$$ guess)

Dave Peterson  (aka: Mr. Vaseline Glass)
webmaster for vaselineglass.org

[mrvaselineglass]

I mentioned I had a custard cup made by PHOENIX GLASS.  This piece actually has 3 layers and the total thickness (at the top rim) varies between .086 and .137 inches (had to play with my digital calipers!).  that figures out from 3mm to 5mm for those who use that measurement.  The close-up shows the three layers at the bottom of the photo.

the outside layer is vaseline, the middle layer is cranberry, and the inner layer is either thin milk glass or something similar. the inner layer is NOT vaseline opalescent, as it does not glow under a UV.  Only the outer vaseline/uranium layer glows.  the inner layer also only goes about 1/2 way down into the cup. 

While this looks like a modern day tea cup, it is actually a custard cup and no saucer was made for it. This piece was made prior to 1900.  The handle is applied and is 100% vaseline glass. 
This photo was taken with no flash:
http://www.vaselineglass.org/phoenixcup.jpg
The left photo on this composite shot was done with flash (the flash tickles the uranium and makes it show green)
the right composite photo shows that the inner layer does not glow.  Due to how thin the uranium layer is, the full fluorescent strip bulb did not penetrate the cranberry layer to tickle the uranium on the outer layer:
http://www.vaselineglass.org/phoenixcupuv.jpg

Mr. Vaseline Glass

[Paul S.]

Dave  -  our sincere thanks for your exceptionally informative contribution - which will no doubt take me a little while to digest and appreciate.   However, I will print and keep as a reference for the future.  :sun:    Paul S.