Jewelry making is a very good guess.After reading all the info/comments so far, I think it is probably a clamp used to grip one or more pieces of wire for twisting. The power bit shank rather insists that it's intended to be spun. I'm thinking that an inexpensive cordless screwdriver would be low enough RPM that the imbalance wouldn't be a problem. Maybe the intended application is jewelry making, to create decorative components. The workpieces could be round, square or ???