Vintage chain, clear rhinestone & baby blue crystal statement necklace

This is a very unique piece that my 99 yr old great aunt had to school me on! lol. it is mainly a black-gunmetal colored chain w/3 large rhinestones on the front (the middle one 2 1/2" H x 2.2" W) with two smaller ones in the middle (1/2" x 1/2") The chain is 17 1/2" - 20 1/2" long... now what really makes this piece special is that just under the top rim there is a row of many blue crystals that are a gorgeous shade that I can only compare to blue aventurine which you don't see very often in crystals on jewelry. they're just gorgeous! I have yet to clean it & I can tell it needs it but I don't clean my jewelry until right before I box it to go out to my customers whether it's brand new or used because I want it sparkling when you get it as well as germ free from anyone touching it throughout it's travels. No worries as I use a top of the line all natural jewelry cleaner :) Great - excellent condition