Humans like to classify things. Our scientific mind organizes the world and represents it according to all kinds of lists, orders and relations. Stones are also classified and one of the ways to identify them is by hardness. Artists also organize the world but in different ways, defying ordinary understanding. The two artists presented this month by Reverso, Edu Tarin and Philip Sajet, use stones in their work and show us how to make the hard stone soft.