Antique Coral & Turquoise Necklace

I've had this necklace in my collection for many years and haven't a clue to how old it may be. The coral drop I added to the necklace. The upper chain part does not look old, may be a replacement. The green round stones look to be glass stones but the other stones look like coral and turquoise. This necklace at one time must have had "drops" hanging from it as you can see little "loops" between each section that must have held dangles or drops. The front and back are gold in color. It measures 17-1/2 inches long. Any info would be appreciated. thanks.