I am familiar with these exact beads.

There are two levels of quality. One is complacent, and the other is excellent. I recently discussed this at my Facebook Group. The glass is so good and bubble-free, I have wondered whether these might be imported European beads, like from a high-class chandelier (?), that were cut in China for their decoration. However, if they were from a Mandarin chain it would be expected that they would be superior to ordinary-quality export beads.

Nevertheless, the only way to be more-certain of their former use would be to find them in the context of such a necklace. But even this is not a guarantee--because "Mandarin necklaces" have OFTEN been re-cobbled-together from leftover parts; and are more-often not original.

These are just nice beads with an uncertain and unknown past.

JDA.