A prototype for a museum experience in which sound becomes material. It was made in a two-day TouchDesigner workshop during the DIGICREA Erasmus Mundus master's, and it starts from how geodes form through accumulation and changing conditions. A rock becomes an instrument: touch generates sound, and sound reshapes an evolving digital mineral through layers, textures and relief. The interaction invites visitors to think about the traces we leave as we move through life, and how individual traces become part of something larger.