This work is entitled Crystals and was commissioned from the artist Pierre Watzky in 2013. It is special because the artist died prematurely just after the City of Mulhouse had approved its purchase. Pierre Watzky had already prepared the models and drawings but it was Roland Vonarzx who finally produced the work from notes and sketches. It represents an ore exploited in mines, here it is a rock salt in its crystalline form, i.e. an imbrication of different volumes of simple geometric shapes. Many then said that cubism had integrated the works of the New Basin. Indeed, there is in this work a work of forms, geometry, volumes. It echoes the life and career of the artist who himself worked at the bottom of the potash mines in the region.