Jade Butterfly Necklace - Need ID help

[twohecticeclectics]

I have this necklace that I am trying to ID.  I have used Google lens extensively but it didn't help me out.  The stamp reads NS or SN.  Butterflies are jade.  Can anyone help with maker?

[evelyb30]

The mark on the clasp may well only pertain to the maker of the clasp, not the maker of the necklace.  By the 80s especially, but earlier too, manufacturers were buying clasps from third parties and using them.  This was especially true for smaller outfits.  Sometimes they'd add a tag or hangtag to identify themselves, but sometimes not.