Forums General Discussion Faceting Blue Topaz

4 replies, 3 voices Last updated by  gemmakermz 4 weeks, 1 day ago
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  • #3375

    Kensington
    Participant
    @Kensington

    Is there any health concerns with faceting blue (irradiated) topaz? The literature from the NRC assures this material is safe to trade/wear, but I wonder about cutting and potential contamination of equipment laps with small amounts of radioactive ions. I’ve already finished the pavilion but this had me wondering a bit.

    #3376

    Alan Balmer
    Keymaster
    @alanbalmer

    You’ve probably already seen this from the NRC:

    “Any dose from these gems would be extremely small. The NRC did a study to estimate the dose to a person wearing a large blue topaz stone (six carats). Assuming the stone had the highest level of radioactivity allowed under NRC regulations, the dose during the first year could be 0.03 millirem (NUREG 1717, page 2-21). Having a porcelain crown or false teeth would give twice that dose (0.07 millirem), while a chest X-ray gives about 60 millirem. But this estimate is conservative. The radiation continues to decay, so the dose rate would go down over the course of the year.”

    As for irradiating a steel lap, that would take a lot more than a few pounds of blue topaz. It’s good to be careful about inhaling microscopic particles of anything, but topaz is a lot safer than stuff you encounter every day. You’ll get about 30 millirems from a year’s consumption of food and water, and 1 millirem from watching TV in a year.

    #3377

    Kensington
    Participant
    @Kensington

    Thanks, I did see that. But it seems there is different methods of irradiating. Not terribly worried, it’s not like I’m faceting a torbenite!

    #3380

    Alan Balmer
    Keymaster
    @alanbalmer

    The method doesn’t matter, because the material has to meet the same max radiation standards. But you’re right, gamma radiation doesn’t make the stones radioactive in the first place, but electron or neutron treatments have to sit for some period of time to “cool off”. All material has to be tested before distribution.

    #5059

    gemmakermz
    Participant
    @gemmakermz

    it is interesting in the treating of topaz. there is heat treating and radiation treating. no problems in heat treated accept that the colors are not natural and in some cases the colors may fade down or away. i gave my cousin a 35 carrat cut white topaz and he got it irradiated at hanford. it was double checked for radioactive content and safety and was very fine and safe. it turned out VERY dark champagne pink and not very brilliant. i took it to and alcohol flame and it started fading back till it was about medium color and the brilliance was there. it has never gotten any lighter in color. some of the rough from Utah and texas and colorado have had natural earthy radiation and when exposed to sun light some do fade to colorless. i have topaz that came out of brazil during the 1930-45 and has not been treared in any way and may be treatable. i do not believe in treating stones to change color true and natural is the way nature created it and i leave it that way. i cut stones that show any signs of color directly down the C axis tipped 5 degrees, this will bring out any color. gemmakermz@cs.com

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