Yet the reality is that the color of a vintage pearl diamond ring can be purple, green, blue, or even black. You might be probably aware that pearl gemstones are not mined from the Earth; instead, they are collected from under the sea. However, the ironic part is that even the ones who harvest oysters in order to obtain pearls will not be able to exactly predict the color of pearl gemstones. Customers who are planning to buy a vintage pearl diamond ring should note that there are three types of pearl gemstones available out there: imitation pearls, cultured pearls, and natural pearls. Natural pearls are the pearl gemstones that form naturally while cultured pearls are the ones that are cultured by men. On the other hand, the term imitation pearls are used to define pearl gemstones that are made from glass beads and fish scales. Even though most imitation pearl gemstones have relatively higher luster, they fade and do not last as long as natural and cultured pearls.