TO BE EXAMINED BY A JEWELLER- NOT FOR SALE YET.
Lavalier Pendant Necklace
GEMS: 15 Diamantes? Rainbow sparkles like Diamonds?
CHAIN:  Snake Chain
In 1857, George Haseltine, a London patent lawyer, applied for a patent for a snake chain
CLASP:  Round opening closing 
METAL:  Gold ?- no marks but acts and look like gold. Some antique gold was not marked before 1906