Gosh. It seems like there's a lot of finger bling in this play. Julia and Proteus exchange rings in Act 2, Scene 3, Proteus asks Sebastian to deliver a ring to Silvia in Act 4, Scene 4, and then in Act 5, Scene 4 "Sebastian" gives Proteus the ring that he, Proteus, originally gave to Julia (back in Act 2). Then, "Sebastian" brags to Proteus that "Julia" gave it to him (5.4). Are you dizzy yet?
Here's the thing. There are only two rings in the play – the ones Julia and Proteus first exchanged when they said goodbye to each other (2.3). These two rings then get circulated to other characters, which means that Proteus gives (or tries to give) Silvia the very same ring that Julia gave him. (Nice guy, huh?)
Silvia, however, doesn't want Proteus's gift. Here's what she has to say when she realizes Proteus is trying to give her Julia's ring:
The more shame for him that he sends it me;
For I have heard him say a thousand times
His Julia gave it him at his departure.
Though his false finger have profaned the ring,
Mine shall not do his Julia so much wrong. (4.4.4)
Ordinarily, rings are supposed to be symbolic of a couple's love and commitment, right? Well, this isn't necessarily the case in Two Gentleman of Verona. We could argue that, by the time Julia's ring reaches Silvia, it has become emblematic of Proteus's deception and his broken promises. On the other hand, we can also argue that Silvia's rejection of the ring (on the grounds that accepting it from a loser like Proteus would hurt Julia and Valentine) is symbolic of her loyalty to Valentine and her sense of allegiance toward another woman.