Discussions

╳Discussions

Groups

Recent Images in Discussions

Generalradioactivity of the blue apatite from Ipirá, Brazil

21st Nov 2011 12:30 UTCJohan Kjellman Expert

Can anyone give any details on the level of radioactivity of the deep blue apatite crystals from Ipirá, Bahia?

cheers

27th Nov 2011 14:53 UTCLuiz Alberto Dias Menezes, Fo.

I have never tested it, I will do it tomorrow.

30th Nov 2011 14:53 UTCLuiz Alberto Dias Menezes, Fo.

Johann:

I tested blue apatite crystals from Ipirá and I got, in 30 seconds, 46 counts, what was about twice the counts (26) I got on a green apatite from Sapo mine of similar size; but on both cases the total counts can be considered low; I used a Russian counter I got from Mikon but I still did not have time to read the instructions manual to be able to talk about the significance of the numbers.

30th Nov 2011 16:09 UTCDennis Harries Expert

I have looked into some of my old ICP-MS analyses, and the Ipira apatite has about 920 ppm Th and 64 ppm U. Durango apatite has only about 20% of these values, so Ipira should be somewhat more radioactive.

30th Nov 2011 18:00 UTCKelly Nash 🌟 Expert

I have a picture posted here at http://www.mindat.org/photo-415859.html that, as noted in the caption, I measured with a pretty sensitive gamma-detector (Ludlum Model 17, recently calibrated) and found to emit about 10 microrems per hr., vs. a background level of about 7. So it's slightly radioactive, but not very much so.

30th Nov 2011 18:08 UTCJohan Kjellman Expert

Luiz and Dennis,

thanks, bought a handful in Munich for our museum shop and got wary when I saw that it was radioactive

bot no cause for alarm then.

hope to be in Munich next year and hope you'll be there too Luiz

cheers/johan

23rd Sep 2014 10:44 UTCYadong Sun

Hi Johan,

I tested Ipira light blue apatite by using the XRF. Th is ~ 600ppm. But this value is not calibrated because it is too high, we don't have a standard.