Natural History - Boxed Polished Amethyst Crystal Obelisk Group [3]

Polished to highlight the various inclusions. 6.21 grams, 40 mm



Property of the vendor's father, thence by descent. From the private collection of a New York, USA gentleman.

Comprising three Petraster sp. specimens, each on a matrix. 1.3 kg total, 9-12.5 cm



From a Cambridgeshire, UK, collection.

A rare complete set of folded-card polyhedrons, each with extensive printed notes on the surfaces, dimension and properties; to be assembled from the 120 components into two adjacent cuboids within a wooden box with hinged lid and paper insert announcing 'Géométrie Stéréométrique -ou- Décomposition du cube en polyèdres réguliers, irréguliers et corps ronds... par L. Dupin Ing.eur' (Stereometric Geometry or the disassembly of the cube into regular and irregular polyhedrons and cylinders... by L. Dupin, Inventor). 463 grams total, 23.3 x 12.3 x 6.7 cm (case)



Private American collection, New York, USA. This lot has been checked against the Interpol Database of stolen works of art and is accompanied by search certificate no.12065-211002.

The box contains an educational set of geometric shapes comprising 120 individual three-dimensional cardboard pieces with printed names and numbers corresponding to the key, arranged in various smaller interlocking configurations. The producer, Louis Dupin de la Guérinière, was a French civil engineer who began to produce and sell folded models to show the physical properties of polyhedrons. His models were intended not only as educational aids for students of mathematics, but also for those whose work involved perspective drawing, stone-cutting and mineralogy. The sets began production in the 1840s and were a popular study-aid. The present example has an adhesive label in the lid naming the supplier as Crosti of Rue Ste. Catherine, Bordeaux, France.