ericw
Well-known member
- Joined
- Jun 7, 2017
- Messages
- 633
I have broken drills too, even treated bits, in tahitian pearls. It's possible that even a hard nacre nucleus is suffisant to curve the drill through softer black nacre around, when the tool meets the nucleus. But sometimes, little stones are used as nucleus of baroque pearls, as I have found several, and then it doesn't work right!