Russia
Nicholas I Proof Poltina (50 Kopecks) 1837 CПБ-HГ, St. Petersburg mint, Bitkin-241, Severin-3214, PR 64 Cameo NGC. Obv. Crowned double-headed Imperial eagle in circle. Rev. Date and value in wreath. Light golden toning, with deeply mirrored fields that contrast nicely with the frosted devices. The surfaces display only a few tiny marks. This issue is extremely rare in Proof and this example is the only Proof certified by either NGC or PCGS. Ex: Sincona Collection, Part 1, October 9-12, 2012. Lot 947.
Estimate: 65000-75000 USD