Blyberg Porphyry Cup - 19th Century

Cup.
Swedish Blyberg porphyry. 
19th century. 

Of all the varieties of porphyry mined in the Alvdalen region of Sweden, Blyberg porphyry is one of the rarest and most sought after.
The rediscovery of porphyry in the 18th century, amplified by the Egyptian campaigns driven by Napoleon, made the Alvdalen deposit famous. Different veins of porphyry were discovered within the region during the 1730’s and their color varied from purple to green.  
Nicknamed the stone of the emperors by the Romans, this rock of a hardness superior to tempered steel requires an extremely complex polishing work and was therefore reserved for the crowned heads.
Napoleon will dedicate a great admiration to this material and it is under the impulse of the former marshal of the empire Jean Baptiste Bernadotte, newly elected king of Sweden and Norway under the name of Karl XIV Johan, that the manufacture will know an international effervescence. Abundant orders were made by the allies of the coalition : Russia, England, Prussia...
As he kept strong friendships in France, Bernadotte also reserved some rare pieces in porphyry of Blyberg for his friends marshals, and will offer diplomatic gifts to the French ambassadors and politicians.