French Green Clay (montmorillonite) doesn’t necessarily come from France, though the clay was originally a French export and most of what is available is from France. Thus it was named accordingly. However, deposits of this green clay are also found in the US and parts of Europe.
The green color comes from the contained decomposed plants. French Green Clay has deodorizing and absorbing properties and is often used in cosmetics, such as facial masks, and also in poultices.