These come from the Rabari tribe of Gujarat, India, makers of some of the most dazzling tribal garb.
The ear wire is thicker gauge than your average western ear wire. I think it is about 14 gauge, or 1.66 mm wide. So these are best for slightly gauged ears. (or you can slightly stretch your own earlobes and open up a whole world of tribal earring possibilities!)
The earwires and the wire wrapping appear to be sterling while the cube at the bottom seems top be a lower grade silver alloy.