Blue Stone Sterling Bracelet and Earring Set

Outstanding Vintage bracelet with large 2" blue ovals and matching 1 and 1/2" clip earrings. Both the earrings and bracelet are marked. The bracelet measures 8" long. There are some slightly visible "spots" under one of the ovals that don't detract from the piece. Very unusual! Not sure what the stone is - looks like blue moonstone but I really don't know what it is.  

I know they made this bracelet with obsidian and onyx, so know it was made with gemstones, and this has does have moonglow characteristics.  Marked Del Rio Hecho en Mexico 925 and Sterling.  The marks are rubbed and hard to photograph but I included one that I attempted!