Diamond Crown of Bulgaria

The Diamond Crown of Bulgaria (Bulgarian: Диамантена Корона на България) was a part of the Bulgarian royal regalia (along with the Sceptres of Ferdinand I and Boris III), that existed during the Bulgarian monarchy from 1878 to 1946. The Bulgarian government ordered the crown as a national present at the occasion of the wedding of Princess Marie Louise of Bourbon-Parma to Prince Ferdinand I. It was made by the Viennese jewellers Köchert.

Source: Wikipedia — Diamond Crown of Bulgaria (CC BY-SA 4.0)