Grey sea salts from the prestigious salt ponds of Guérande France are completely natural and unrefined. These salts are harvested using traditional Celtic methods. The beautiful grey color that comes from the clay lined salt ponds that the seawater is evaporated in. The exceptional French clay in these ponds adds valuable minerals and nutrients that add to both the nutritional value and flavor of these fine salts. Le Trésor salts are never blended always 100% pure sea salt from Guérande France.