Monazite, a Rare Earth Minerals rich mineral found in many parts of the world, from India, to Brazil.
This sample contained thorium, which made it radioactive.
Bionerd23 basking in Monazite-rich sands in Brazil: https://www.youtube.com/watch?v=vdHHUGwFoJE
My spectrum of the sample: http://anti-proton.com/monazite.png