He says that part of the reason the Marie Antoinette pearl is worth so much is because it's a natural pearl, which brings us to one quality that determines a pearl's value. Natural versus cultured.

The Bahrain Institute for Pearls and Gemstones (DANAT) recently hosted an educational workshop on natural pearls for students ...

However, both natural and cultured pearls come in various colors of the rainbow — from white to black — including blue, green ...

South Sea pearl-shells are common, with white edges. The beautiful dark green pearl-shells called ear-shells or sea-ears, are more concave than the others, and have small holes round the margin ...

Pearls are made by marine oysters and freshwater mussels as a natural defence against an irritant such as a parasite entering their shell or damage to their fragile body. The oyster or mussel slowly ...