The exploitation of ocher around Apt owes everything to Jean-Étienne Astier who, between 1780 and 1785, studied the properties of the yellow and red sands of his land in Roussillon and was the first to have the idea to separate ocher from sand. In 1790, he received authorization to use the village's oil mill to make ocher. Twenty years later, Jean-Étienne Astier operated two factories near Apt and a factory in Roussillon itself to the chagrin of the population worried about the atmosphere pollution and hostile to the ocher dust that encrusted to the heart of its habitat.