The gold found on the banks of the Rhine originated in the Swiss Alps, and gold can still be panned in the Rhine today.
The first German coin that bears an inscription denoting its gold origin is a half ducat from the Electors of the Palatinate minted in Heidelberg.
On the reverse, under the coat of arms is EX A RH, indicating “Ex Aureum Rheni,” which means “From Gold of the Rhine.”
Aside from the Electors of the Palatinate, the Grand Duchy of Baden, the Archbishops of Mainz and the Kingdom of Bavaria also minted coins from Rhine gold.
Another source of river gold was the Danube and its tributaries, the Isar and the Inn. The gold found here also originated in the Alps and has been harvested since medieval times.
A very limited amount of gold was recovered from the Eder River in North Hessen.
This gold originated from the Eisenberg (Iron Mountain) near Korbach in the Prinipality of Waldeck. The coins were minted by the Landgraves (later Electors) of Hesse-Kassel.
The practice of striking gold ducat coins from alluvial gold continued from 1674 until 1863, with different cities striking coins at various times and quantities, with the river not always identified as the source on earlier coins.
The first ducats carrying the name of a river were minted in 1756 in Munich, from gold harvested in the Danube River. All these coins have various dies, combinations and variants, Neumann said.
In addition, several medals were made from river gold, as well as from silver recovered as a by-product of the refining of the river gold.