Antique ( Vintage) stamped as well as Sterling on this Rare whistle necklace

Antique Whistle necklace black onyx with marcasite and a beautiful pink center stone . The chain is stamped as well ( note ) the mesh type chain has minor denting , roughness. Still wearable but you can feel the roughness with your hands . The chain is original to the original whistle so I definitely did not want to change it . I could not find another like this . It’s very rare . See all pictures, to see sizing conditions