Dating to the 1980s may I offer from an estate here in the St. Louis area, this necklace of dark green jade beads - more than likely Nephrite Jade. The beads are strung on dark green string and are knotted between each bead. The necklace appears to be quite secure on the string but at some time in the future, I am sure a restringing will be needed. Fish hook clasp that appears to be just yellow gold tone metal. The previous owner spent a lot of time in the Orient and I have no doubt that this necklace was one she purchased there - most likely Hong Kong.
Condition is very nice with no problems I can spot. Green coloring is consistent with flecks of black/brown. The beads are not consistently round as modern beads would be; definitely indicates hand polishing. Because of these qualities, I believe the beads are undyed and completely natural.
Metal Content: Gold tone metal findings with no hallmarks
Size: Length of the necklace is about 23". The jade beads measure 10mm.
Weight: A hefty 71.9 grams.
Final Comments: Leave as is or take the beads apart and use in other projects. This necklace is priced to sell!