Mica-Fe comes from the “Massif de Saint-Sylvestre (Massif Central) in France. It was taken from two mica-bearing granites. Micas are often used for radiometric dating employing the Rb/Sr method. It classifies as a Biotite.
HerkunftMassif de Saint-Sylvestre (Massif Central) in France
The main components are SiO2 (34.4 g/100g), Al2O3 (19.5 g/100g), Fe2O3 (25.65 g/100g) and MgO (4.55 g/100g).
It is very rich in fluorine, F with a proposed value of 16000 µg/g and also Li (1200 µg/g).
Rb and Sr have concentrations of 2200 and 5 µg/g respectively.
The chemical composition of minerals, the Earth's building blocks, is of interest for both industry and science.