Uranium glass
Uranium glass, also known as vaseline glass, is a pale yellow or yellow-green glass made by the inclusion of uranium.
The first creator of uranium glass is believed to be Martin Klaproth, the discoverer of uranium. It is believed that among his experiments with the element that he mixed it into glass as a coloring agent.
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 Reidel, who named the yellow and yellow-green varieties of the glass "annagelb" and "annagrün", respectively, in honor of his wife Anna Maria. Reidel was a prolific blower of uranium glass in Dolni Polubne, 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.
By the end of the century, a variety of uranium glass with certain additional minerals made under high-temperature conditions could be tempered to change from its normal transparent yellow or yellow-green, to increasing opacity and ultimately opaque white. This style of uranium glass 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.
While uranium glass was originally used widely in the production of tableware and other decorative household items, it has long since fallen out of use, except in the form of marbles for use as novelties or in science experiments. Most other objects made with this glass are considered antiques or retro-era collectibles.
Regular uranium glass flouresces 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. However, the radioactivity of the glass is widely considered to be negligible and not harmful.