Mabe pearls have an oval form. They grow on the inside surface of a valve. They are also called blister pearls or “blue pearls”. The mollusc which produces this kind of pearl is called Pteria Penquin which is translated as “golden oyster’s wing”. When an oyster reaches 13 cm in diameter, one or two hemispheres are implanted into the mantle of the mollusc. After the implantation 10-15 pearls are attached to the pearl-shell in one row through special holes. Then the pearls are cultured in the farm up to 14 months. Akoya pearls are 2-9 mm in diameter. Oysters are collected when they reach 5-10 cm in diameter. Molluscs which produce this kind of pearls are called Pinctada fucada or Vulgaris. A bead is surgically implanted into the gonads of the mantle conjunctive tissues which serve as a “pearl bag”. After the procedure molluscs are controlled to be sure that the implantation went alright. The pearls of this kind are cultured for 8-24 months. South Sea Pearls are the biggest of all the kinds of cultured pearls. They are known for their beautiful satin lustre and warm colors. A pearl has a size from 9 to 20 mm. Pinctada Maxima oyster which is used for the production of the pearls can reach 30 cm in diameter which allows to implant larger beads. Pearl shells are usually harvested after 2 years. In the farm oyster shells of different colors are cultured to get pearls of white, silver, pink, gold, cream color and any combination of these basic colors.