Hi Fiona,
My impression is that if the pearls look really good, the layer of nacre is acceptable. But this goes only for SSP and Tahitians. Akoyas are notoriously thin-skinned. I think the point is in part, as I've said before, that pearls are a commodity - like a car. You can spend an awful lot of money on a car, well-knowing that it will wear out. The nacre layer will be worn away little by little, the rate being dependant on how often you wear them, the acidity of your skin, perfumes, etc. If you want to be sure, the best would be to buy all-nacre fresh water pearls.
- Karin
Yes, agree. You know that I did hours and hours of reading here but only realised how thin nacre could be recently. Took a while for the penny to drop, which I have to assume would be the case for most pearl laypeople. The Akoyas in particular. My questions were more to the heart of how quickly might nacre in bead nucleated pearls wear out and could you always tell. I am definitely a fan of freshwaters and Catherine Cardellini has been brilliant in helping me feed my addiction in a 'safe nacre' way!