Re: Irradiated gemstones

["J.J. Rozental" <rozental@unisys.com.br>]

What NRC writes about gemstones today is quite different than 20 years ago.
"Some gemstones, such as blue topaz, can be given a more pleasing color
using neutron radiation treatment.

Although there might be some residual radiation from neutron bombardment of
gemstones and other consumer products, the half-life of these materials is
generally so short (seconds or hours) that risk to the public is extremely
low. To ensure that the products are manufactured correctly, manufacturers
and distributors of these materials must be licensed by the NRC."
Reference:
The Regulation and Use Of Radioisotopes in Today's World (NUREG/BR-0217)
http://www.nrc.gov/NRC/NUREGS/BR0217/br0217.html
and:
 The NRC's information is not true: The main impurity of gemstone is Sc-46,
half life 84 days (not seconds or hours) that oblige the owner to keep the
gemstone be protected  for about 2 years before permission to open market.

Jose Julio Rozental
rozental@unisys.com.br

Rio de Janeiro, Brazil

By the way,  the NRC requirements can be found at the following site:
NRC INFORMATION NOTICE NO. 90-62: REQUIREMENTS FOR IMPORT AND DISTRIBUTION
OF NEUTRON-IRRADIATED GEMS
http://www.nrc.gov/NMSS/BPR/infonote/1990/in90062.htm

About the first reference:


----- Original Message -----
From: <RTPhysics@aol.com>
To: Multiple recipients of list <radsafe@romulus.ehs.uiuc.edu>
Sent: Wednesday, January 26, 2000 7:29 PM
Subject: Re: Irradiated gemstones


> The blue color of topazes were being inhanced at the University of
Missourri
> reactor in 1984, they had a small robot arm to pick up the jems and sort
them
> by activity.  Many could not be release on the market because they were
too
> hot and are being stored some place.
>
> Rich Tupper, MSc, DABR former health physicist
> East Orange VA Radiation Therapy Department
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