Vintage Green Turquoise Gaspeite Sterling Silver Station Statement Necklace

I bought this gorgeous necklace at auction with several Native American pieces and it is SO unusual! The heavy silver chain features five heavy set gaspeite stones in lovely hand worked sterling "frames" AND it has matching earrings. The back of the center necklace stone is hallmarked "HN" and all pieces are marked sterling. The necklace measures 20.5: long, I did see a few Running Bear cuffs that had similar stones and they were marked as gaspeite, so that is my best guess to the stone? It is very nicely made and heavy. Thanks for looking and feel free to ask questions.