How Are Pearls Cultured? A Detailed Guide to Pearl Cultivation Methods and Techniques

Pearls are a raw material used to make jewelry and can also be used for beauty and skincare, so how are pearls cultured? What varieties of pearls are there? Let's take a look!

I. Basic Introduction to Pearls

A pearl is an organic gemstone, a mineral bead containing calcium carbonate formed by the endocrine action within the bodies of pearl oysters and mother-of-pearl mollusks. China's natural freshwater pearls are mainly produced in the islands of Hainan. Pearls come in five color series: white, red, yellow, dark, and variegated, and most are opaque.

The inorganic components of pearls are mainly calcium carbonate and magnesium carbonate, accounting for more than 91%, followed by silicon oxide, calcium phosphate, Al2O3, and Fe2O3, etc. The shapes are diverse, including round, pear-shaped, egg-shaped, teardrop-shaped, button-shaped, and irregular, among which round is the best.

Natural pearls are spherical, oval, irregularly spherical, or oblong, with a diameter of 1-6 mm. They are hard in texture, difficult to break, and have a layered cross-section. When burned with fire, they make a crackling sound. They have no odor and a slightly salty taste.

II. How Are Pearls Cultured?

Select pearl oysters with intact shells, full interiors, and healthy, undamaged conditions for cultivation. Then, through surgery, implant small pieces of tissue and a nucleus into the shell, place the pearl oysters into net cages, and suspend them in water with ropes for cultivation. Generally, pearls can be cultured in 1-2 years.

However, if the water temperature is too high or the temperature difference changes too drastically, it will cause the metabolism of the pearl mussels to become imbalanced. If the pH is too low or too high, the pearl mussels cannot adapt either. During the cultivation of pearl oysters, attention must also be paid to the prevention and control of pests and diseases.

III. What Varieties of Pearls Are There?

1. Akoya Pearls

Produced in the coastal bay areas of southern Japan. The mother-of-pearl oyster is called Akoya. This variety is perfectly round, with strong luster, mostly pink or silvery white in color, and generally 6-9 mm in diameter.

2. South Sea Pearls

Natural or cultured seawater pearls produced in coastal countries of the South Pacific. The pearl-producing oysters are mainly the large mother-of-pearl oyster or the Pinctada martensii. The main producing countries include Australia, India, Japan, Indonesia, the Philippines, Myanmar, and Thailand.

3. Freshwater Pearls

The vast majority come from China, with output accounting for 80% of the world's total. The mother-of-pearl oyster is the hybrid Pinctada martensii or the freshwater mussel. The roundness and luster of freshwater pearls are the main factors affecting their price.