Posted 11 years ago
belleverre
(79 items)
Today I am posting a Loetz PG 7624, Prod #7724/8, on ruby glass. They appear to have quit making ruby glass in or about 1900. I expect this may be because ruby glass is more expensive and requires more experience from the gaffer. Any other ideas? (2006)
Stunning as always!!!
Great vase! I love your collection. Just beautiful.
Yes, "beautiful glass". I believe they stopped making the red mostly because of the expense (adding gold makes the glass red) but I suppose expertise must have played a role. I love this shape and color for the 7624. Very beautiful.
I have always heard that red Tiffany was very difficult and expensive to make. Hence its rarity in the marketplace and the high prices it continues to demand today. I could only assume the same thing for Loetz at the time.
The three most common elements used for making red glass are copper, selenium, and gold. Copper is used for most everyday red glass such as vases, stoplights, etc. The shades are slightly different but the ranges can overlap. Fredrick Carder used gold and selenium in his Steuben glass, and I don't know if Tiffany used anything other than gold. Judging from the large ammount of red glass that they made, and its shade, and the fact that they tightly controlled costs, I suspect Loetz used mostly copper for theirs. Has it ever been analyzed?
Great information belleverre! I would like to add that these elements (copper, selenium, gold) became scarce around WW1. Selenium, for example, was a German export that ceased in 1914.
A brief explanation for why red glass is more difficult to make. When first mixed and melted the glass is clear colorless or slightly amber. While it is worked at the furnace it stays in that condition. To achieve the red color it must be cooled a certain ammount then reheated another certain ammount. When reheated the glass "strikes" the red color. As you might guess it takes a lot of experience, especially under the primitive conditions in 1900.
Fascinating ...
Combine that with the intricacies of trying to manage the intricacies of the iridescent surface finishes and their multiple components and you could lose nights of sleep ...
This could also be a significant part of the reason that the PG decors never achieved the Ruby color that is evident in the Rubin Matt Iris pieces ...
Master Craftsmen or simply Great Artists ... The results suggest both!
Thanks for the info ...
Don't think anyone has been brave enough to break one (other than Al's neighbour's plumber) to do the analysis ... I have a "blaze gated spectrograph" here and a CCD camera ... do you think this setup could produce meaningful results ?
In my missive above I failed to mention what happens if the timing is off when reheating the glass. It will turn an ugly shade of liver, which would probably not be very marketable. Possibly the exception to this problem is Tiffany who produced several flowerform vases that have a white or amber feather pattern that has a brownish border. These don't compare to those having red borders. I just happen to have a similar Tiffany flowerform vase that has a red border which I intend to post soon.
I appreciate and am enjoying all of the great dialog. Thank you.
SteveS- I know generally what a spectrograph does but otherwise you lost me.
Hi BV
... was just thinking you could send a few pieces over ... and I would be happy to commit a few years to studying them ... :-))
What I have is a Baader Planetarium "Blaze gated lens" (Laser-cut diffraction grating) is made for fitting in a Telescope eyepiece / objective to capture the absorption spectrum (rather than emission - I think) of the various heavy elements in star light / star dust ...
This should fit the problem ... the transmitted light would need spectral analysis (matching) ... should be able to derive some info from that without any damage ... not sure if this is being done anywhere at present ... Not sure if the PG surface treatments would mess it up ... not sure if a light bulb would be a powerful enough source ...
Many variables ... needs to be done one day ...
Hello SteveS-
Iwill be happy to send my glass pieces over to you for study......as soon as I am finished studying them myself. It may be a while.....after thirty years of study, it seems that I'm just barely getting started.