Saltwater pearls were historically seen as financial assets since thousands of oysters had to be searched to find just one pearl. Today, freshwater pearls are cultured in mussels that live in lakes and ponds. This precious gemstone is June's birthstone. Shell pearls are made from the shell of an oyster by using the shell as the raw material for the base then coating and polishing the final shape of the pearl. Many people favor the modern technology of pearl production because of its guaranteed durability. The shell pearl keeps its shine and color, and is not affected by perfume or detergents.