Hello :) I have had this strand for 20 years now. I bought them at Macy's in late 1990-early 2000. I have had re-stung 2x now. Worn a lot. 14kt stamped clasp. Pearls measure roughly 6mm, uniform. What type are these and what happened? Looks like nacre chipped or peeled off by drill hole. The ones pictured are worse, but
