Putin pockets Superbowl ring

AP is reporting (link via Yahoo) that Russian President Vladimir Putin now has a Superbowl ring:

Russian President Vladimir Putin walked off with New England Patriots owner Robert Kraft's diamond-encrusted 2005 Super Bowl ring, but was it a generous gift or a very expensive international misunderstanding?

Following a meeting of American business executives and Putin at Konstantinovsky Palace near St. Petersburg on Saturday, Kraft showed the ring to Putin — who tried it on, put it in his pocket and left, according to Russian news reports.

It wasn't clear if Kraft, whose business interests include paper and packaging companies and venture capital investments, intended that Putin keep the ring.

I know that Superbowl rings are relatively enormous, and not the sort of thing that you'd wear casually. Does one of them qualify as a typical gift given to foreign heads of state? Would it cause an international incident to give an ugly piece of jewelry to the head of a former superpower?