I was recently given a four strand gold pearl necklace purchased in the Philippine Islands in the 60’s. I am questioning their authenticity.
How do I tell?
You have asked a great question, are they in fact pearls from an oyster, or man-made?
This comes up quite often as people inherit jewelry from family members. And, in fact it is fairly easy to know.
The Pearl Test: The simple test is to rub them one pearl against another (you can rub fairly hard).
Pearls cultured from oysters are gritty in feel even thought they may look smooth. Natural or cultured pearls will have that gritty feel when you rub them together, while faux pearls feel smooth.
You can also rub a pearl against your teeth, if you like, and your real pearls will give the same impression of grittiness.
This is due to the fact that the organic substance deposited by oysters consists of microscopic crystalline plates, whereas man-made pearls are beads of glass (or plastic) coated in one or more layers of varnish. Some are even dipped in a mixture which includes ground-up fish scales to add some luminescence.