Vintage Sterling Silver Brooch Spinning Stones Jasper? Crescent Shape Filigree.

Beautiful vintage sterling silver 925 crescent shaped brooch with spinning center stones. The smooth, polished stone cabochons are a deep green-blue/dark teal on one side, mottled purple stone on the other. (I believe both stones to be types of Jasper, but I am not certain). They are both joined together with a silver encasing band and spin on the top bar of the brooch. The silver crescent has a raised/bas-relief filigree design. Overall good vintage condition with some scratches to silver, patina/tarnish. Pin is in working order. Please see all pictures. Measures approximately 2 1/2” in length and 1 5/8” from top of cabochons to bottom of arc in the silver crescent.