The Mysterious Glow of Vaseline Glass

QUESTION:  

My aunt recently died and left me several things, including two beautiful twin yellow-green glass vases. I don’t know much about them but someone said they’re made of Vaseline glass. Does that mean they use Vaseline to make them? Can you tell me more about this beautiful glass?

 

Thanks,
Andrea

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ANSWER: No, your vases aren’t made of Vaseline. The most common color of this type of glass is pale yellowish-green, which in the 1930s led to the nickname "Vaseline glass" based on its resemblance to the appearance of Vaseline brand petroleum jelly as was formulated and commercially sold at that time.

The addition of uranium dates back to Roman times. Professor R. T. Gunther of the University of Oxford discovered a piece of glass containing one percent uranium dating to 79 C.E. in an excavation of an imperial Roman villa on Cape Posillipo in the Bay of Naples, Italy in 1912.

Starting in the late Middle Ages, workers extracted pitchblende from the Habsburg silver mines in Joachimsthal, Bohemia. This was then used as a coloring agent in local glassmaking. Austrian druggist Franz Xaver Riedel experimented with pitchblende and obtained a yellow substance later identified as uranium dioxide. He added it to glass and became the first major producer of items made of yellow-green uranium glass, which he named "annagrün" (annagreen), in honor of his daughter Anna Maria. By the middle of the 19th century, this new coloring agent became popular in both Europe and America.

Vaseline glass is also called "uranium glass." This mineral added to glass is what makes it glow bright green under blacklight. The normal color of uranium glass ranges from yellow to green depending on the oxidation state and concentration of the metal ions, although this may be altered by the addition of other elements as glass colorants.
That bit of uranium in the glass also makes it slightly radioactive.

With improvements in mass-produced, affordable glass, the popularity of vaseline glass rose. During the second half of the 19th century, interest in the glowing glass peaked. The fashionable glass was appealing both in sunlight and in the evenings. Victorian homes were lit by gaslight, kerosene or candles, which produced soft light-The human eye sees yellow-green most easily since it is in the center of the spectrum of colors, so under flickering light con. lit ions, the Vaseline glass seems to glow.

Large glass companies like Fenton Glass and Moser Glass made vases, tableware, tooth-pick holders, clocks, whimsies, shoes, hats, parasols, inkwells,. compotes, and more in Vaseline glass. But between 1890 and 1910, the middle class became more interested in pottery and porcelain. With the development of Incandescent lighting, the steady light frequency made Vaseline glass appear plain.

The government confiscated all supplies of uranium during WWII for the Manhattan Project and halted all production of vaseline glass for from approximately 1942 until the ban was lifted in November 1958. From 1959 onward, glass companies began making vaseline glass again. However, because of the expense to obtain uranium dioxide, production was and is still very limited.


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