Le Grand-Fougeray

Le Grand-Fougeray monazite placer, derived from shales of the Ordovician Traveusot Formation, is the largest and the best documented of the placers in Brittany. Estimated tonnages in alluvium of the Aron and Gras rivers are modest (1900 t of monazite in clayey gravels with a grade of 2 to 2.6 kg of monazite per ton, and a cut-off at 1 kg/t). However, this monazite is exceptionally rich in europium (0.2 to 1 per cent Eu₂O₃); it also contains neodymium (13 to 14 per cent Nd₂O₃) and is poor in thorium (<1 per cent ThO₂).References

1. https://en.wikipedia.org

2. http://www.eurare.eu/countries/france.html

3. http://www.greenplanet.pro/encyclopedia/geography/korsika/

4. http://picsfab.com/image/nature-corsica-korsika-priroda-71141

5. 87429a871771208554b30b1914d47561

6. https://hal-brgm.archives-ouvertes.fr/hal-00942683