The École des Mines de Saint-Étienne possesses an important collection of wooden crystallographic models. Rehabilitation action was undertaken. Several series of Krantz models were identified by the logos and linked to catalogs. An exceptional element was discovered: a polyhedron with 170 facets, from the cubic system. We report on the digitalization work, followed by a description of two duplication methods: 3D printing and precision lost-wax vacuum casting.