What is a cultured pearl?
A "natural pearl" forms in the wild without any human intervention at all and is very rare. Many hundreds of pearl oysters or pearl mussels have to be gathered and opened and therefore killed, in order to find even one wild pearl, and for many centuries that was the only way pearls were obtained. This was the main reason why pearls fetched high prices in the past.
A "cultured pearl" is formed in a pearl farm, using human intervention as well as natural processes and the vast majority of 'real' pearls are cultured. Nowadays, most freshwater cultured pearls are farmed in China.
Types of cultured pearls
Keshi pearls are a byproduct of the culturing process, and do not happen without human intervention. They are produced from many different types of marine mollusks and freshwater mussels in by returning the shells, post-harvest, to the water to regenerate a pearl in the existing pearl sac. They are irregular in form with wonderful lustre.
The original Japanese cultured pearls, known as Akoya pearls, are produced by a species of small pearl oyster, which is no bigger than 6 to 8 cm in size, therefore Akoya pearls larger than 10 mm in diameter are extremely rare and highly priced. Today, a hybrid mollusk is used in both Japan and China in the production of Akoya pearls, which take 2-4 years to form.
Black Tahitian Pearls
Tahitian pearls are highly valued because of their rarity – they take 2-7 years to form; the culturing process means can never be mass produced. This is due to a low survival rate, rejection of the nucleus and their sensitivity to changing climatic and ocean conditions. Before the days of cultured pearls, black pearls were rare and highly valued for the simple reason that white pearl oysters rarely produced naturally black pearls.
South Sea Pearls
A South Sea pearl is a pearl produced by the Pinctada maxima pearl oyster and they take 2-7 years to form. South Sea pearls are the colour of their host and can be white, silver, pink, gold, cream. South Sea pearls are characterized by their warm lustre and large size. Sizes up to 14 mm in diameter are not uncommon. South Sea pearls are primarily produced in Australia, Indonesia and the Philippines.
What is Lustre?
The unique lustre of pearls depends upon the reflection and refraction of light from the translucent layers: The thinner and more numerous the layers, the finer the lustre and the iridescence that pearls display is caused by the overlapping of successive layers. In addition, pearls, especially freshwater pearls, can be dyed yellow, green, blue, brown, pink, purple, or black.
Lengths of pearl necklaces
There is a special vocabulary used to describe the length of pearl necklaces. While most other necklaces are simply referred to by their physical measurement, pearl necklaces are named by how low they hang when worn around the neck.
- A collar, measuring 10 to 13 inches 25 to 33 cm) in length, sits directly against the throat and does not hang down the neck at all; collars are often made up of multiple strands of pearls.
- Pearl chokers, measuring 14 to 16 inches (35 to 41 cm), nestle just at the base of the neck.
- A strand called a princess length, measuring 17 to 19 inches (43 to 48 cm), comes down to or just below the collarbone.
- A matinee length, measuring 20 to 24 inches (50 to 60 cm), falls just above the bust.
- An opera length, measuring 28 to 35 inches (70 to 90 cm), will be long enough to reach the breastbone or sternum of the wearer.
- A pearl rope, measuring more than 45 inches or 115 cm in length, is any length that falls down farther than an opera.