It looks like a "Moretto" by Nardi venetian jeweler :
"The “moretto” is an item of jewelry that best encapsulates the classical image of Shakespeare’s Othello and the refined goldsmith’s techniques of 18th-century Venice.
Dressed in his characteristic clothes and turban, the blackamoor, or “moretto”, is embellished by the infinite styles and combinations of its creators’ unbridled fantasy and skill.
Depicted as either a token of love or as a caring companion, it possesses the exquisite merits of a beautiful and unmistakable Venetian jewel or those of a precious souvenir that has always been desired and sought-after by royalty, elegant women and famous personages."