This is a Tiger's Eye gemstone bib necklace. It's an original work of Nouveau Boutique. There are triple strands of 12-14mm button shaped beads as bib and 10mm round beads for the rest of the necklace. It comes with a brass spring clasp with four rings that make the necklace adjustable from 16.5 to 18 inches.
Dimensions: 16.5-18 inch adjustable