1852, Oldenburg (Grand Duchy). Copper 1 Schwaren (3 Light Pfennig) Coin. Mint Year: 1852 References: KM-185Denomination: 1 Schwaren (3 Light Pfennig) Material: Copper Diameter: 16mm Weight: 1.31gm The House of Oldenburg is a European royal house of North German origin. It is one of Europe’s most influential royal houses with branches that rule or have ruled in Denmark, Iceland, Greece, ...