Giorgione
It may be the work that Giorgio Vasari saw in Giovanni Borgherini's home in Florence, which he recorded as produced by Giorgione in Venice during Borgherini's youth. A 1568 edition of Vasari's Lives of the Artists states "In Florence by his [Giorgione's] hand in the house of Giovan Borgherini's sons [is] the portrait of the same Giovanni, when he was young in Venice, and in the same painting his tutor guiding him; one can see in both heads finer tints of shadow than in any other work". It was probably commissioned by Giovanni's father Salvi Borgherini, who was in Venice with his son from 1504 onwards.
In this horizontal portrait painting, two men with peachy skin are shown from the chest up against a black background. One man holds a brass-colored sphere made of interlocking bands. To our left, a young boy or man gazes at us with dark eyes, his coral-pink lips parted. His curly brown hair falls to his shoulders, and he wears a floppy, denim-blue hat.
To our right, a man leans toward the boy, shown almost in profile. He has ash-brown curly hair and a hint of a short beard on his chin. His hooded eyes, prominent nose, and parted downturned lips are evident. He wears a honey-yellow tunic over a white undergarment, with a swath of scarlet red, possibly a cloak, over his left shoulder. In the space between them, he holds up an armillary sphere with his right hand, its overlapping bands forming an orb. A long white scroll wraps around the handle of the sphere, his hand, and down to his wrist. He looks at the sphere and points to it with his other hand.
P.S. Many people know Titian but very few (apart from art lovers) remember Giorgione, who was one of the most important Renaissance painters! Here's all you need to know about Giorgione!