What kinds of thread have been used for pearl stringing since the art of adornment began? When could our ancestors have starting using pearls as adornment and how?
Much of the known history of spun fiber is relevant to pearls, whether the spun silk that is all the rage now, or the ropes that were used to aid in pearl diving, (of which we have a record going back to the 4th millenia BC in Bahrain).
The thread on 'cave pearls' mentions shells as the earliest ornament found-dating back to 95,000,years ago. Here is that link
Some younger shells dating from 75,000 years ago clearly show the marks from the thread used which were most likely 'drilled' with a sharp slice of flint.Now that we are on the topic, I would like to expand our studies a little to that of spun fibers, ie thread or cord. In a very quick google search, not looking past what shows up on the search page, I saw a claim that the oldest piece of fabric or textile found, was in Turkey and it is over 8,000 years old, yet it already showed "great skill".
'Great skill' means the warp and woof thread were very finely and evenly spun. Spinning fine thread is much harder technically than spinning coarse plant fibers, but it uses the exact same technique: you have a bundle of fibers lined up in the same direction and you pull some partially out of the bundle and twist it. Then you keep pulling the twisted part to draw out the parts of the bundle that got caught in the twist and keep on spinning.
One good question is how old is the use of a drop spindle?
I would bet, that the very fibers that made marks of wear on those ancient shell ornaments will also yeald up microscopic hints of twist. This would indicate a spun fiber was used. My bet is actually a testable hypothesis though we must wait for the experts to comment on it based on their findings re this discovery.
BTW I tend to get fuzzy on details, so please feel free to correct me and to add your own opinions....
Thanks to DFrey for pointing out the oldest shells did not have the thread marks, (though they were assumed to be worn as adornment)