On an exceptional sample of wooden crystallographic models from the collection of minerals at the École des Mines de Saint-Étienne (France): description, history, digitalization, duplication

Abstract. The École des Mines de Saint-Étienne possesses an important collection of wooden and terracotta crystallographic models (several hundreds). During the 2000s, enhancement rehabilitation action was undertaken. Several series Krantz were identified by logos linked to catalogs. relation these work Paul Heinrich von Groth, in cooperation with company, is highlighted. An exceptional element discovered: a polyhedron 170 facets, from cubic system. After short description model, we report on digitalization work, followed two duplication methods: 3D printing precision lost-wax vacuum casting.