Earrings for Men

My husband was kinda (OK very) wild through high school and most of college -- mostly punk, but lots of other sartorial variations. He settled into khakis-and-button-down-shirts anonymity for a while through grad school and postdocdom because it was convenient in many ways, and is slowly branching out again, fashion-wise, as his position as a professor becomes more secure.

He still has two pierced ears (one piercing in each), though he hasn't worn earrings in about 10 years. We just tried last night, they still "work" (haven't closed up). We were musing about what kinds of earrings he would wear, thought I'd put it to fashion-conscious guys here.

I suggested small diamond studs, he thought that was too cliche, not the kind of effect he was going for. He thought maybe he'd wear these brass/ "gold" hoops he used to wear, I think they're way too hippie/ oversized wool fisherman's sweater/ birkenstocks. (Both of which he wore when he wore those earrings.)

I think he'd want something interesting/ a bit edgy, without going overboard.

Any ideas?