An ammonite pair, Speetoniceras sp., Russia, Jurassic Period (146-208 million years old), Estimate £3,500 – 4,500 (€3,500 – 4,500). Photo Bonhams.
Cut and polished, partially pyritised, on perspex display stands, 16.5ins.(42cm)wide, each. (2)
Note: A desirable ammonite from the Volga River. The presence of large amounts of iron during the fossilisation period results in pyritisation: a striking combination of Aragonite, Gold, Silver Pyrite crystals and brandy coloured Calcite.
Bonhams. GENTLEMAN’S LIBRARY SALE. 27 Jan 2015 11:00 GMT – LONDON, KNIGHTSBRIDGE