Historical specimen from the collection of Dr. Henri-Léon Ungemach*. Is features lustrous cuboctahedral crystals of acanthite from Freiberg, Saxony (Germany), on a calcite matrix. The specimen is in pristine condition!.

It comes with the original labels of H.L.Ungemach* (1), two from the University of Liege (2, 3), and one from the Jozef Cosemans collection (4).

*Henri-Léon Ungemach (1879-1936) was a chemical engineer, PhD in mineralogy from Strasbourg. Ungemachite was named after him.

The Ungemach collection was acquired by the University of Liege (ULB) in the '30s, and registered piece by piece in the official catalogue. The original label that reads “argyrite” (sample #6147) was handwritten by Ungemach. The other number (#3163), corresponding to the ULB Catalogue, was handwritten (in blue) by Professor Dr. Joseph Mélon (Mélonjosephite). Over the years the ULB exchanged duplicated specimens with other institutions or private collectors. In addition we add here a picture of that original catalogue of the ULB where it can be read that the acanthite #3163 was exchanged ("échange"), but no date was registered.

We thank Prof. Dr. Frédéric Hatert (ULB) for the picture of the catalogue.