A vintage pair of screw back earrings by Margot Van Voorhies Carr in sterling silver with blue and white enamel.  The blue enamel part has a dotted background.  Measure 1 1/8" long and 3/8" across. 

Screw backs hold securely.

Marked Sterling, Hecho en Mexico, Eagle # 16, and some other things that are hard to read on the backs. 

Beautiful enamel work.