Hi -
your spoon was made in Moscow by Kolotoschin, Aleksej F. (1835-1849) in the year 1843, assayed by Kowalskij, Andrej Antonowitsch also 1843. This spoons were made of silver 84 Zolotniki (875/1000) and decorated with niello. See photos of the spoon how it should look....
Regards
Zolotnik