AW: Radioactive vinegar bottle ?!?!

["Franz Schoenhofer" <franz.schoenhofer@CHELLO.AT>]

-----Ursprüngliche Nachricht-----

Von: owner-radsafe@list.vanderbilt.edu

[mailto:owner-radsafe@list.vanderbilt.edu]Im Auftrag von Kolb, William

(WKOLB)

Gesendet: Montag, 16. September 2002 18:36

An: 'Bob Westerdale'; radsafe@list.vanderbilt.edu

Betreff: RE: Radioactive vinegar bottle ?!?!





Bob,



Ivory glass or Custard glass was made with uranium oxide in amounts ranging

from 0.1 to 10 percent to obtain an opalescent to opaque white glass

beginning in the mid 1880s. One way to test for the deliberate presence of

uranium rather than tramp contaminants is to expose the glass to UV light.

It will glow a bright yellow green under both long and shortwave UV.



---------------------------------------------------



Bill,



Are you sure, that it was uranium oxide? White opaque glasses were produced

in Europe using tin oxide (Milchglas, "milk glass") and bone ash (Beinglas,

"bone glass") already several centuries ago. I could imagine that also

titanium oxide and especially zirconium oxide would be suitable as well.

Both tin, titanium and zirconium ores are known to contain traces of

thorium, which might in some cases be considerably high. Therefore this

might be an explanation for the activity of the bottle.







Uranium was used to produce yellowish glass ("Annagelb" - "Anns yellow"),

which is relatively rare and greenish glass ("Annagruen" - "Anns green").

Anna was the first name of the wife of the owner of the glassworks, which

first produced it. To my knowledge also black glass was produced by using

uranium, but none of the black glasses from my glass collection show

enhanced radioactivity, but I never had problems to demonstrate the

radioactivity of my green uranium glasses. Since long time uranium is not

used any more in Europe for manufacturing green glass, cheaper and

non-radioactive alternatives are known. The best way to distinguish them -

except radioactivity - is UV light, there are very cheap small lights

available. Glazes produced with the help of uranium salts (they are orange

to red) do not fluorescence in UV light.



The color is an inherent feature of the glass, caused by the chemical

properties of uranium. It cannot bleach and anyway the uranium glasses are

transparent, so the glass could not become white. (What can bleach is the

color induced by radiation in crystals or glass at very high doses.)



Best regards,



Franz





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