Zanetti spent his early manhood making wise investments in
marine insurance, accumulating sufficient capital to support his true vocation, as a writer and artist, and as an art dealer, doing much of his business with the English aristocrats who passed through Venice on the
Grand Tour. He acted as paintings agent for
Philippe d'Orléans in forming the
Orléans collection, Paris, and
Joseph Wenzel I, Prince of Liechtenstein, in expanding the
Liechtenstein collection, Vienna.
Pierre Crozat, being in Venice in 1715, persuaded Zanetti and his protégé
Rosalba Carriera to go to Paris. Zanetti also visited London, where he purchased Jan Petersen Zoomer's three large volumes containing 428
Rembrandt etchings in outstanding impressions of the various states. He formed a collection of
engraved gems, both Greco-Roman and modern, of which he published a lavish catalogue, in the form of
A.F. Gori's
Le gemme antiche di Anton Maria Zanetti (1750), illustrated with eighty plates of engravings from his own drawings. The drawings for the engravings, and many of his intaglios and
cameos, are conserved in the
Museo Correr, Venice. His prize piece, a black intaglio of Hadrian's favourite,
Antinous, which he had pursued for years before acquiring it, was bought by
George Spencer, 4th Duke of Marlborough and gained the sobriquet of the "
Marlborough gem". As a
printmaker, Zanetti advanced the art of the
Chiaroscuro woodcut, producing many prints after paintings by
Parmigianino,
Tintoretto and others. On 4 November 1750, in response to Zanetti and
his homonymous cousin having dedicated a book to his father
Christian VI, King
Frederick V of Denmark and Norway awarded each of them a gold medal adorned with diamonds, and also offered
noble status, along with a
grant of arms, in
Denmark and
Norway. However, learning of the fees involved, the Zanetti cousins returned the
letters patent to
Copenhagen, explaining that they didn't see themselves served with other nobility than the one that the emperor had granted to their ancestors. ==Further reading==