READ THIS!!!!!
Right. I just thought I'd share the Infallible Test for real pearls (whether saltwater, cultured, freshwater, cultured freshwater etc.)
I lived in the Far East for some time and visited IMMENSE pearl markets, where we learned how to test for a real pearl. This was in a very poverty stricken country (the Philippines) yet you could get freshwater pearl studs for about 10p, and everyone - I mean EVERYONE - had a pair, however poor, and everyone knew the test.
So - you get 2 pearls and rub them together firmly but gently. There should be what looks like a scratch on the surface, as a tiny tiny deposit of the powder that 'forms' the pearl lifts off. This can simply be smoothed away. You can also gently scrape one against your front tooth, and you will have a sort of grinding, dusty sensation.
A fake pearl will seem smooth, and they will just slide over each other.
When we went to the Philippines I brought home lots of pairs of earrings as gifts and a beautiful string of large white well-matched pearls that cost me about a tenner.
I took them to a jewellers here to be knotted and re-strung, and he was dumbstruck but their quality and wanted to know where I'd got them.
I had intended them to be an heirloom (they were that beautiful) but within 3 weeks were stolen from a hotel room in Stratford-Upon-Avon. I never forgot them and that was 10 years ago now 