Multi Gemstone Necklace stamped 925 prong set

Multi Gemstone Necklace stamped 925 China on the slide closing clasp ( has snap down safety lock mechanism see pic 7 for a closeup) , prong set gem stones . When I purchased this I was told it was "Sterling silver multistone with 18K yellow gold overlay Amethyst , citrine, white topaz, peridot and garnet " , pic 13 is the info I received with this pretty necklace. Mannequin's neck is ~ 15", tape measure in pics shows, ~ 17" long necklace. Very pretty classic style . weighs 22 grams on my kitchen scale see pic 15. Questions are always welcome . Nice Valentine's gift . Date night. wedding, cocktail party , special occasion piece.