1. Mica

1.1 Origin of the base material

Mica, a crystalline rock, originates in areas of very high geological compression, which is why the main extraction sites are all located at the foot of major mountain folds, such as the Alps, the Andes and the Himalayas. In France, it is also found at the foot of the Massif Central. Mica rock is generally exploited in mines and, occasionally, in open-cast quarries.

The mica group (from the Latin micare: to shine) comprises a wide variety of minerals, chemically very diverse, but with the common characteristic of cleaving extremely easily to form thin blades or flakes with a characteristic semi-metallic luster.

Classification according to chemical composition allows us to distinguish four main species,...