This coin is a coronation thaler struck to celebrate the coronation of King Wilhelm And Queen Augusta on 18th October 1861.
Other Prussian thalers show only King Wilhelm I on the obverse but this one shows Queen Augusta as well. In total there were 1,000,000 coins minted and many were saved in celebration of the king and queen coronation which does make them a little less rare than some other coins of this era.
The coin is excellent condition for its age and has not been cleaned. Containing around a half ounce of silver it is a largish coin and quite solid to hold. A lovely addition to coins from this era and one that collectors recognize as a good investment.