Uranium glass
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Uranium glass, also known as vaseline glass, is a pale yellow or yellow-green glass made by the inclusion of uranium oxide. Uranium glass typically contains about 0.1% to 1.3% uranium (by weight).
The use of uranium glass dates back to at least 79CE [1], the date of a mosaic containing yellow glass with 1% uranium oxide found in a Roman villa on Cape Posillipo in the Bay of Naples, Italy by R. T. Gunther of the University of Oxford in 1912.[2][3] Starting in the late Middle Ages, pitchblende was extracted from the Habsburg silver mines in Joachimsthal, Bohemia (now Jáchymov in the Czech Republic) and was used as a coloring agent in the local glassmaking industry.[2].
Martin Klaproth (1743-1817), the discoverer of uranium, later experimented with the use of this element as a glass colorant.
Uranium glass became a popular form of glass in the mid 19th century. The first major producer of items made of uranium glass is commonly recognized as Josef Riedel, who named the yellow (German: Gelb) and yellow-green (German: Gelb-Grün) varieties of the glass "annagelb" and "annagrün", respectively, in honor of his wife Anna Maria. Riedel was a prolific blower of uranium glass in Dolni Polubny, Bohemia from 1830 to 1848.
By the 1840s many other glassworks throughout Europe began to produce uranium glass items, including new varieties of uranium glass. The Baccarat glassworks of France created an opaque green uranium glass which they named chrysoprase, for its similarity to the green form of chalcedony with that name.
At the end of the 19th century, it was discovered that uranium glass with certain additional minerals could be tempered at high temperature to partially crystallise, changing from its normal transparent yellow or yellow-green with increasing opacity to, ultimately, opaque white. This material, technically a glass-ceramic, inspired the name "vaseline glass" due to its similar appearance to petroleum jelly. Today, this term is the preferred term for all varieties of uranium glass, especially in the United States.
Uranium glass was originally used widely in the production of tableware and other decorative household items, but has long since fallen out of general use, and is most likely to be found as marbles for use as novelties or in science experiments. Most other objects made with this glass are considered antiques or retro-era collectibles, although there has been a minor revival in art glassware.
Regular uranium glass fluoresces bright green under ultraviolet light due to the uranium content. Certain other varieties will glow other colors. Uranium glass is scarcely radioactive, and a sufficient quantity will register on a sufficiently sensitive geiger counter above background radiation. Although the radioactivity of the glass is widely considered to be negligible and not harmful, it is still recommended that exceptionally large collections be kept behind leaded glass.[citation needed]
[edit] See also
[edit] External links
- Uranium Glass - The Glass Association
- Uranium Glass at the Glass Encyclopedia
- Davidson English Pressed Glass at the Glass Museum
- Radioactive Marbles at United Nuclear
- vaselineglass.org
- Vaseline and Uranium Glass at the Health Physics Historical Instrumentation Museum Collection
