Striking Vintage Necklace Onyx Gemstone

This lovely vintage necklace offers shades of orangey/brown beads with some specs of green within some of the polished gems. The gems gradually get a bit larger towards the center of the necklace. The cord is a rich red and each gem has a red knot tied between them. A certified gemologist/jeweler inspected the necklace and reported the gems are likely from the onyx family. The necklace measures 27" end-to-end and is weighty at approximately 80 grams. It feels great to the touch. Questions welcome. From a smoke free home.