Grandmothers real natural pearls

by Japa Khalsa
(New mexico)

I have a set of real pearls from the 1950s. my grandmother was wealthy and bought a graduated set and was told they were real. They are still beautiful slightly pinkish in color and pass the " gritty" test. they feel slightly gritty when you gently rub your teeth on them. My mom gave them to me because she said I could always sell them for a bunch of money if I needed to. But how can I verify that they are natural pearls ? Do I need to get them x rayed ? How much are they really worth ? Thank you