“Lenticular siderite crystals with minor white quartz. FOV is ~26.5 cm. Specimen formerly belonging to the Crida collection. This collection, consisting of 2,060 specimens, was donated in the mid-1950s to the City of Turin by the heirs of Dr. Celso Crida (1867-1950), a Piedmontese medical doctor and mineral collector, and is presently part of the Museo geo-mineralogico collections, Politecnico di Torino, Turin, cat. no. MP/9880. Photo: Paolo Bosio, 2019. The specimen was displayed in the special exhibition titled "Minerali a Torino - Le collezione dei Musei e dei circoli mineralogici torinesi" at the Turin Mineral Show, October 4–6, 2019. ”