Vintage Turquoise Necklace with Barrel Clasp

Measures approximately 18 inches long. 

Turquoise Aqua color beads.  There are 3 designed like bigger beads in the middle. Looks like all the beads go through a wire. 
This came from my mothers estate and I do not know how old this might be.  Seems very well put together.  

This is a very interesting piece of jewelry.