Almost unbreakable, this rock constitutes much of the crust of our continents and the root of our mountains. This rock, considered as the base of the terrestrial world, is granite. To better understand its relationship to living organisms, we will travel to the United States, where researchers are trying to understand how such a hard rock influences plant life. In Namibia, we will follow the footsteps of funny animals, the Agamas, who cultivate a pronounced taste for the mineral. In France, we will start at the foot of the Massif de Bavella where we will discover the walls that climbers love so much. We will then go to Brittany where granite, the source of many beliefs, has changed the course of history; then in Alsace where the granite soil influences the flavor of wines, among the best in the world.