42mm Antique Czech chrysoprase jadeite Uranium green sharks tooth pendant glass bead

42mm Antique Czech chrysoprase jadeite Uranium green sharks tooth pendant glass bead. A very early hand molded pendant bead in stunning original condition.
Origin: Northern Bohemia circa 1900's

Size: 42mm; 1.65"

Uranium glass is glass which has had uranium, usually in oxide diuranate form, added to a glass mix before melting for coloration. The proportion usually varies from trace levels to about 2% by weight uranium, although some 20th-century pieces were made with up to 25% uranium.

Uranium glass was once made into tableware and household items, but fell out of widespread use when the availability of uranium to most industries was sharply curtailed during the Cold war in the 1940s to 1990s.

The normal colour 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. Uranium glass also flouresces bright green under  ultraviolet light and can register above background radiation on a sufficiently sensitive geiger counter, although most pieces of uranium glass are considered to be harmless and only negligibly radioactive.

The Baccarat glassworks in France created an opaque green uranium glass which they named chrysoprase from its similarity to that green form of chalcedony.