After a rather long and somewhat turbulent period in my life, I finally found a moment to write this post. Today's topic will be focused on minerals. It's been a while since I last went panning for gold in the area near Golčův Jeníkov in the highlands. We found some gold back then, but what was equally interesting was the amount of heavy minerals left in the bucket. I didn't have time to investigate the composition in detail, but at first glance, the most abundant minerals appeared to be rutile and pyrope, and here and there, you could also spot a small zircon crystal. I decided to keep about 140 g of the concentrate for further investigation.
It could be said that for almost 20 years, this concentrate of heavy minerals has been sitting in my drawer under the label "I will come back to it someday." Well, now the time has come. I thought it would be interesting to put the concentrate on a gamma spectrometer just for fun. To my surprise, after a few dozen minutes, a perfect spectrum of the uranium decay series appeared. I probably shouldn't have been surprised, as even the average educated hobby mineralogist knows that such concentrates regularly contain minerals with rare earth elements and traces of uranium and thorium. So, here it is ...
| Sample | Heavy minerals concentrate 140 g (Czech Republic ) |
| Gamma spectrometer | Scintillix SCGS-01 |
| Scintillation probe | NaI(Tl) 3" |
| Integration time | 97696 (27 h) |
| Background correction | No |
| Shield | Lead |
| Software | Theremino v.7.2 |
As is usuall in similar cases, there are easily recognizable peaks of lead-210, uranium-235, indicating the natural (non-depleted) composition of the sample. Further, there is radium-228, a triplet of peaks belonging to lead-214, and a prominent peak of bismuth-214 at 609 keV.
