Calculating radiation

[Peter-1]

Hello,
I have a very small piece of uranocircit. 3 x 2mm and 0,3mm thickness. This are 1,8 * 10-3 cm³
Uranocircit has ~ 3,5 gr/cm³ . The activity is near 75 kBq/gr. So I calculate 1,8 * 10-3 * 3.5 = 6,3 mg.
6,3 mg * 75kBq = ~ 470 Bq.
Is that correct ?
If you want I can show the spectrum.

Peter

[Sesselmann]

[processing LaTex...]Ba(UO_2)_2 (PO_4)_2 •12H_2 O

Do we have any chemists here who can tell us what this is?

Steven

[Geoff]

Uranyl Phosphate. A secondary ore of uranium. If you live in a dry climate it's likely to have dehydrated to metauranocircite, Ba(UO2)2(PO4)2 · 7H2O. By weight, Uranocircite is about 44% uranium or 50% UO2. Metauranocircite is about 48% uranium or 54% UO2. Unfortunately, I don't know how to calculate activities of ore. As for your sample, if it has any attached matrix or host rock, the mass to activity will be incorrect.

A good resource might be the WISE project: http://www.wise-uranium.org/rup.html#UORE

I actually have a large collection of uranium minerals. The low quality ones get ground up and turned into ammonium diuranate. Here is one of my favorite metauranocircites, this one from Bergen, Germany.

[Peter-1]

Hello Geoff,

I have the values from Wikipedia (Germany).
https://de.wikipedia.org/wiki/Uranocircit

The density : Dichte (g/cm3) 3,46
The activity : Das Mineral ist durch seinen Bariumgehalt giftig und durch seinen Urangehalt von bis zu 43,9 % stark radioaktiv[11] mit einer spezifischen Aktivität von etwa 78.650 Bq/g[2] (zum Vergleich: natürliches Kalium 31,2 Bq/g).

Peter