Pearls - Types and Features

February 16, 2020

Natural Pearls or Cultured Pearls

A pearl is formed when a foreign body (such as parasites or shell fragments) reaches the soft tissues of a mollusk (typically an oyster) and becomes trapped by it.

In order to defend its tissues from irritation, the mollusk covers the foreign body with several layers of mother of pearl (formed mainly of calcium carbonate) , giving rise to the pearl.

Natural pearls are pearls that formed without human intervention.

Cultured pearls are all obtained by human intervention through the procedure of grafting a foreign body (a solid core or the tissue of another donor) into the mollusc tissue.

This means that by entering a plastic fragment with a specific shape, after a certain period of time, it is possible to obtain a pearl with the enlarged shape of the initial fragment.

In jewelry, almost exclusively cultured pearls are used.

The reason is that to ensure a production of pearls that meet the high quality standards required, breeders must carry out numerous checks throughout the mollusc's growth period, which can last from a few months to many years, depending on the type of mollusc. It is necessary to constantly check the quality of the water, its temperature and the plant and animal environment.

Certain categories of oysters require more care and attention than others, they are more delicate and more susceptible to water temperature. The farmers raise or lower the nets on which the oysters lie to keep the water temperature as constant as possible.

In practice it is a continuous surveillance at all times to ensure the success of the crop that would not be possible under conditions of natural development.

Cultured pearls should not be considered a series product. In fact, only a small part of all nucleated oysters (where an artificial nucleus has been inserted) will give life to a high quality pearl.

Many oysters do not survive the nucleation process or are weak and easily attacked by disease. Sometimes, following heavy rains, the salinity of the water in the bays changes, placing the oysters in great pain. Without forgetting the possible attack of external pathogens, such as the so-called "red tide", a particular phytoplankton that runs out of oxygen in the water causing the suffocation of oysters. Finally, there are typhoons and other parasites or predators that lead to an average oyster survival rate of around 50%.

Of these, only about 20% are suitable for jewelry!

The most common color in pearls is white, but pink, cream, dark purple, gray and black pearls can also be found.

When we talk about black pearls, we immediately think of the very expensive Tahiti pearl, very precious and particularly beautiful; in fact, unlike the others, the oysters that create black pearls are much more delicate and in every cultivation many of them die. This is another factor that makes them so expensive and rare.

The value of pearls, however, does not only depend on the color, but also on the shape and luster, that is, the light that manages to reflect.

The shape can be variable:

  • spherical
  • Oval
  • drop
  • irregular (in this case we are talking about bad luck)
  • rice grain

Freshwater Pearls, Saltwater Pearls or Imitation Pearls

There are two categories of pearls: freshwater pearls and saltwater pearls . As the word itself says, freshwater pearls are grown in lakes and rivers, while the rest come from the ocean and very often from the lagoons.

To these is added a third category: imitation pearls , produced by man with different materials, without any direct action by the molluscs.

Freshwater pearls

Since the thirteenth century, freshwater pearls have been collected in China and today China is the undisputed world leader in the production of these pearls. Freshwater pearls boast a wide variety of natural shapes and colors, and tend to be less expensive than saltwater pearls.

Today, thanks to the development of cultivation techniques, freshwater pearls can match the quality of seawater pearls with a brightness similar, if not equal, to the most famous saltwater pearls, with a size that can reach 16mm.

Freshwater pearls are rarely round in shape; the reason is that molluscs raised in fresh water are grafted using only a piece of tissue from a donor mollusk (which does not have its own shape), without a core inside.

However, not having a core, and therefore being entirely made of mother of pearl, freshwater pearls are longer and more resistant than all nucleated pearls.

Freshwater oyster with pearls

Generally a freshwater mollusk produces 24-36 pearls with ripening times from 2 to 6 years.

The magnificent natural colors of freshwater pearls also allow you to create beautiful jewels with pearls, even large ones. (lavender, white, peach, black).

Color freshwater pearls

I decided to use mainly freshwater pearls in the creation of my jewels for sale on my e-Store (come and visit my collection of jewels with pearls ). In this way, in the face of a decidedly low price, I can create trendy and high quality jewelry.

Saltwater Pearls

Saltwater pearls are classified into 3 types:

  • the Akoya;
  • the pearls of Tahiti;
  • the very expensive and rare South Sea (or Australian) pearls.

Akoya oysters die after pearls are collected. The oysters that produce Tahitian pearls and Australian pearls instead survive the extraction of pearls and can be nucleated again producing larger pearls. However, after a few nucleations, the growers leave the oysters quiet so that they can reproduce and favor the restocking of the farm.

Akoya pearls

Akoya pearls are pearls that are produced by Pinctada Fucata Martensii, better known as Oyster Akoya. This mollusk is grown mainly in Japan, China and Vietnam. Renowned for their excellent brightness, Akoya pearls are considered the most classic pearls. They are generally white or ivory / cream, with pink, silver reflections.

Color Akoya pearls

The Akoya oyster is the smallest pearl oyster and produces pearls that measure from 2 to
10mm maximum. They are generally perfectly round or almost and are ideal for creating jewels of great brightness and charm, which is why they are the most commercialized and known pearls.

South Sea or Australian pearls

Australian pearls are the largest cultured pearls in the world. The average size of a pearl's diameter is approximately 13 mm, with diameters ranging from 9 to 20 mm.

The production areas where it is possible to grow such large sizes are limited, also for this reason these pearls are extremely rare. Australian pearls are produced by the Pinctada Maxima oyster and are grown between the Indian Ocean and the Pacific Ocean, mainly in Australia, but also in the Philippines and Indonesia.

Only a small percentage of Australian pearls are perfectly round and, therefore, making a perfectly round and homogeneous pearl necklace is often a very long and complicated job to make and can take several months.

There are two varieties of Pinctada Maxima: the one with silver lips and golden lips.

Australian oyster silver lipsAustralian oyster golden lips

These are distinguished by the different colors of the outer edge of the inside of the shell which determines the color of the pearls that are produced. These oysters allow only one nucleation at a time, i.e. only one nucleus is inserted. The oyster is "nucleated" when its development reaches half its size, approximately between 12 and 17 cm, or around 24 months of age.

There are several factors that contribute to reaching such large diameters for Australian pearls: the size of the oyster, the size of the core that is inserted and the time frame, usually several years, in which the pearls are left in the oysters.

Finally, the production area, as the waters of the southern seas are generally very clean, warm and full of plankton, the favorite nourishment of Pinctada Maxima.

Australian pearls have a slight variety of colors, generally white, silver and golden. These are rare colors in the other pearls.

Australian pears color

Black pearls of Tahiti

Tahitian pearls are produced by the black-lipped oyster Pinctada Margaritifera, throughout the archipelago of French Polynesia.

This oyster is large in size and can reach, although in rare cases, 30 cm in length for a maximum weight of 5 kilos. The large size allows this oyster to produce large diameter pearls.

Giant oyster from Tahiti

Tahitian pearls are unique for their natural black color, they are the only naturally dark cultured pearls. In fact, the color of these pearls is never truly black, there are absolutely no black pearls in nature; Tahitian pearls have shades ranging from gray, silver, to green with fantastic reflections of peacock green, bronze, silver, pink, aubergine and others.

Color Tahitian pearls

Although they are known as Tahitian Pearls, in reality the homonymous island of Tahiti is only the commercial center of the archipelago, currently there are no black-lipped oyster farms on the island. Cultivations of Tahitian pearls extend from the east in the Gambier islands of the archipelago of French Polynesia to the west in the islands of Micronesia.

I can make jewels with all types of salt water pearls , but I do it only on commission ; at the moment you won't find them on sale on my e-Store for 2 main reasons:

  1. the higher cost of salt water pearls reduces the number of sales, and since we are a small goldsmith laboratory, we currently have a limited warehouse that we prefer to use for the most requested products;
  2. for a higher cost for the customer than for freshwater pearls, I prefer to create a personalized jewel using the type of saltwater pearl (color and size) chosen by the customer, instead of being the one who proposes the jewelry " already ready".

So if the world of salt water pearls has fascinated you, write me specifying which jewel of my collection you like and with which pearls you would like it to be made and I will give you a totally free and no obligation quote.

Imitation pearls

Pearls were already imitated in antiquity. Clay spheres covered with mica powder cooked in the remains of cremated Indians have been found. At the time of the Romans, glass beads were produced which were silvered and covered with glass.

There are several types:

  • Parisian pearls or blown pearls are very thin, hollow glass beads filled with different materials and systems. The first inner layer was covered with the so-called "essence of the east", a paste obtained with fish flakes and "fish glue", which has excellent iridescence.
  • The pearls of Rome consist of a solid spherical core, often of alabaster, coated with a mixture of fish gelatin, shiny oyster flakes and mother of pearl powder.
  • The pearls of Venice or Murano are glass spheres to which, in the fusion, substances are mixed which give a pearly appearance.
  • Majorca pearls are obtained by covering glass spheres by repeated immersions in an organic compound derived from fish scales; the final immersion in acetate or cellulose nitrate polymerises the organic material, making it harder and more resistant to shocks and ultraviolet radiation.
  • The tub pearls are mostly made of mother of pearl spheres immersed in multiple baths of iridescent substances composed of synthetic resins . They are also marketed under the name of resin pearls, angel, mikomo, takara, sheba and misaki.

If you want to wear a trendy jewel with quality pearls, bright and perfectly round at an affordable price, come and have a look at my collection of Jewels with Pearls .


Here ends our little journey into the world of this ancient gift of the purest waters of distant seas, which has always enchanted and seduced for its ethereal beauty.

Synonymous with femininity and refined simplicity, each pearl is unique in shape, color, shine, size: this is their greatest value, what makes them so precious. They never repeat themselves and nobody can ever wear the same gem of the sea.

So, if you also want to wear a UNIQUE jewel, come and discover all my jewels made with pearls with a modern design and make this small miracle of nature a faithful accessory of elegant beauty.

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Size guide

How to calculate the size of a RING

To calculate the size of your ring you can measure:

Look for the diameter in the table below to find the right size:

15.3 mm 48 mm 8
15.6 mm 49 mm 9
15.9 mm 50 mm 10
16.2 mm 51 mm 11
16.6 mm 52 mm 12
16.9 mm 53 mm 13
17.2 mm 54 mm 14
17.5 mm 55 mm 15
17.8 mm 56 mm 16
18.1 mm 57 mm 17
18.5 mm 58 mm 18
18.8 mm 59 mm 19
19.1 mm 60 mm 20
19.4 mm 61 mm 21
19.7 mm 62 mm 22
20.0 mm 63 mm 23
20.4 mm 64 mm 24
20.7 mm 65 mm 25

How to calculate the size   of a BRACELET

To find your ideal size, wrap a measuring tape around your wrist, just below the bone. Pull the tape so that it is snug, but not too tight.

Write your circumference and we will find the right size for you based on the bracelet chosen or choose from the proposed sizes.

How to calculate the size   of a NECKLACE

In the image below you can see roughly how the necklaces of different sizes fit. Choose yours!