Vintage Marquise Blue Stone and Aurora Borealis Rhinestone Pendant Necklace

vintage brass tone pendant with aurora borealis rhinestones and a large blue marquise cut stone in great vintage condition ~ there is one very small ding on the blue stone (pictured) I have it displayed here on a vintage very tarnished gold tone chain with a spring ring clasp, which I will include measurements: chain ~ approx 18" long pendant ~ approx 1.75" including bale