Pearl is regarded one of the most sought after jewelry. It can be created in various types of shelled mollusk, such as conch shell, mussel, abalone, and oyster. Yet, only pearl oyster and pearl mussel can create jewelry-grade pearl.
Pearl is formed inside the shell of mollusk. Its formation process is similar to how our eyes produce tears to wash out irritants when our eyes come into contact with them. When irritants, such as grain of sand or rocks, enter the shell, the mollusk, being irritated, will secrete nacre to coat the irritants.
Generally, pearl can be classified into two types:
- Saltwater pearl
- Freshwater pearl
Saltwater pearl, which is also known as Orient or Oriental Pearl, can be found in Gulf of Mannar (between India and Sri Lanka), Gulf of Mexico (between Mexico and Venezuela), Australia, and some island nations in the Pacific.
Freshwater pearl can be found in major rivers and has a larger varieties compared with saltwater pearl. However, its quality is generally inferior to that of saltwater pearl due to pollution and fisheries in rivers.
Both saltwater and freshwater pearls are results of natural process and are created spontaneously in nature. However, due to an increasing demand for natural pearl, there is not enough natural pearl to meet the demand, resulting in a dramatic decrease in a number of natural pearl. Consequently, pearl cultivation technique is invented and creates the lucrative Cultured Pearl business.
The cultured pearl cultivation process imitates natural pearl formation process, and can be done in both saltwater and freshwater. Most of the cultured pearl farms are located in Japan, where small oysters are raised in marine farms in the ocean for three years before being used to produce pearls.
To begin with, oyster is brought onshore, where it will open up its shell to breath. The pearl farmer will use a small wood to pry the oyster and keep the shell open, then insert an irritant, such as a small shell with mantel tissue from other oyster. The oyster is then placed back in the ocean to allow the mantel tissue to grow and eventually becomes a fine pearl. Generally, the process takes two to three years to complete. However, a rapid increase in demand for pearl incentivizes pearl farmers to harvest the pearls sooner before they should.
South Sea Cultured Pearl, which is famous for its large size, is one of the most wanted seawater cultured pearls. It is cultivated mainly in Australia, but can also be found in Indonesia, the Philippines, Papua New Guinea, and Thailand.
Like other gemstones, pearl is constantly refined and developed to improve overall quality. It is even imitated by other types of gemstones or objects, which will be further elaborated in our next article.