Molasse
It is rough and full of small pieces of gravel and fossil fragments. This rock, called molasse, was deposited in a hot sea, not very deep, which was full of oysters, scallop shells, coral, sea urchins and sharks: the Luberon, 20 million years ago. In French, the word 'Molasse' can be spelled with one 'l' or two. The spelling with one 'l' denotes "mola", meaning "millstone" in French, as this abrasive rock was used to sharpen the grinding wheels in mills, but it can also denote "mollis", the word for "soft" in French, as although it is not soft, it's easy to carve and hollow out. The numerous quarries and cave sites in the Luberon bear witness to this.
