PEARL SORY - Kitamura pearls created by the sea and people of Tsushima -
How pearls are made
From raising the mother oysters that produce pearls, to inserting the nucleus, curing, releasing the pearls, collecting the pearls, and processing them.
We will introduce you to the process of pearl farming, which takes up to four years and is done entirely by hand.
Seedling collection
The first step in pearl farming is the collection of young Akoya oysters, which are the mother oysters of pearls. In the past, female divers would collect Akoya oysters that naturally grow in the seas of Mie and Nagasaki and use them as mother oysters, but now most of them are grown by hand from young oysters.
Mother oyster farming and oyster cleaning
Young Akoya oysters are placed in culture cages and suspended in the sea for one to two years to watch them grow. During this time, the shells are cleaned to remove sponges, seaweed, oysters, and other debris that can hinder the opening and closing of the shells. Once the shells have grown, they are selected and only the best ones are used for pearl farming.
Egg-less (rannuki)
Cultured pearls are created through a process called "nucleation," in which a nucleus is inserted into a mother oyster. However, the period during which nucleation can be done is extremely limited throughout the year, and extending that period even just a little has long been a challenge. One solution is "ran-nuki," which artificially encourages oysters to lay eggs and completes the process quickly. This process is called "tate," and the quality of the pearls is greatly affected by the quality of the pearls.
Shell stand/bottle holder
To insert the nucleus, the shells' mouths must first be opened. To do this, the shells that have been successfully prepared are first moved from the egg-removing basket to another basket, where they are packed tightly together with their mouths facing upwards. The shells that are unable to open their mouths find it difficult to breathe, and in reaction, they open their mouths wider. This is the process known as "kaitate". After that, a wedge-like opener called a "stopper" is inserted and fixed in place, known as "stopper insertion".
About the nucleus
Let's take a moment to talk about the "nuclei" that are inserted into the mother oysters. When pearl farming first began, most small 5mm nuclei were used due to technical issues. However, since the technology to insert larger nuclei was perfected, the domestically produced shells that had been used until then were not thick enough, so most shells now come from overseas. The main shells used are the brown sea mussel, which lives in the Mississippi River basin in the United States, and the thick part of their large shells is ground into a spherical shape and used as the nucleus.
Cell cutting
The next step is a process called "cell cutting," in which the mantle of the Akoya oyster is cut into small pieces about 2 mm long, taking advantage of the pearl oyster's ability to secrete nacre. Cells cut from the mother oyster into which the nucleus will be inserted are called "symbiotic cells," while cells cut from another oyster are called "long cells."
Nucleus insertion
Now it's time for the nucleus insertion process. The nucleus insertion technician inserts the spherical nucleus and cells into the oyster. This is a very delicate and difficult process, and it takes at least 10 years of experience to become a fully trained technician. If the insertion is done incorrectly at this stage, the oyster will weaken and die, or the pearl will not grow properly.
Curing (temporary hanging)
After the nucleus insertion process, the treated oysters are in a weakened state due to considerable damage. Rather than simply suspending them in the ocean, they are temporarily suspended in a place where they can be easily seen by humans for a while, and their recovery is carefully monitored. This process is called "curing."
Okidashi (Hon-tsuri)
After the temporary suspension, the treated oysters are transferred to the main rafts offshore, where the full-scale cultivation process begins. It usually takes one to three years for a fine pearl to be born.
Even during the final hanging process, cleaning and other care of the mother oysters is essential. If the oysters' condition is not taken into consideration, they may die quickly due to changes in the environment or spit out their precious pearls. This process requires experience and steady effort to identify and accurately respond to changes in the ocean.
Pearl harvesting (beach harvesting)
We are finally approaching the "beading" stage, where the pearls are extracted. However, even if all the steps are followed smoothly, not all oysters will be brought up bearing beautiful pearls. Some oysters die before reaching the beading stage, and even if they do make it this far, only a very small number of them produce pearls that are beautiful enough to satisfy the eye.
The harvesting period varies depending on the time of nucleus placement, location, and natural environment, but generally takes place from December to February of the following year. Some pearls are test-husked, and those in the best condition are "taken off the beach." Once removed from the oysters, the pearls are rubbed with salt to remove any dirt adhering to their surfaces, then washed and dried.
Sorting and processing
The dried pearls are then sorted one by one by skilled eyes, who examine the color, shape, luster, and flaws. Any pearls deemed unmarketable at this stage are rejected.
The pearls selected here are usually sent from the farm to a processing company where they are individually finished and processed. To be made into products such as necklaces and rings, holes are drilled, the strands are assembled, and metal fittings are attached.
After going through such a long process and time, the finest pearls are delivered to our customers.