This sample comes from the Freiberg Bergakademie and is accompanied by a label from the end of the 19th century and beginning of the 20th. In this old label we can read that the specimen was identified as monazite. To corroborate this fact together with the other accompanying minerals, we proceeded to carry out analyzes by SEM-EDS. The results indicated that the crystals from honey to dark tones, with a vitreous luster, correspond to monazite-(Ce), which is accompanied by rare earth elements such as neodymium or lanthanum, replacing cerium. We also detected the presence of thorium, which explains why the piece shows some radioactive activity. In the potassium feldspar matrix, with quartz, we can observe small black crystals with a metallic luster that would correspond to members of the columbite-(Fe)-columbite-(Mn) series. We have also detected a thorium phosphate-silicate with REE and aluminum traces, with a composition similar to enalite, an independent member of the xenotime-thorite group, although we have not been able to confirm it. We will send the buyer all the analyzes that give this specimen a remarkable mineralogical value.

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