Art Deco Sterling Silver Camphor Glass Purple Rhinestone Filigree Lingerie Necklace

Dating to the 1920s/1930s or so, here's a Sterling Silver (hallmarked on clasp as pictured) lingerie necklace - negligee necklace. Meant to position itself between the bosom of a lady, the necklace is composed of a fine link chain and ends in a pendant section comprised of 2 pieces. First, there is a clear rhinestone set within a filigree setting and, at the bottom, a pendant set with a piece of camphor glass and topped with a marquise cut, faceted dark purple glass paste (open back). The chain section measures 16"; the 2 parts comprising the drop measure 1-3/4" long x 7/8". wide. Weight is 5.7 grams. Condition is very fine with no problems I can spot. There is still a fair amount of tarnish on the piece - I did not polish completely letting the "age of time" show through. A hard to find piece of antique jewelry these days.