What are Pearls and where do they come from?
Everyone knows what a pearl is, but how much do you really know about pearls? In this article, we’re going to take a deep dive (pardon the pun) into the pearl’s aquatic world and try to better understand these small, and not so small, wonders of nature grown.
Key Takeaways
- Pearls are formed inside molluscs, like oysters and mussels, pearls are organic gemstones rather than mined gemstones.
- Different pearl types come from different pearl shell, grown in different environments.
- Saltwater pearls, like Akoya, South Sea and Tahitian pearls differ from Freshwater pearls.
- A pearl’s lustre and iridescence come from the nacre, layers of calcium carbonate and protein secreted by the mollusc around an irritant or nucleus.
- Most pearls today are cultured, and cultured pearls are real pearls.
Summarise this article
How are pearls formed?
Pearls are formed as a natural defense mechanism. When an irritant is introduced into the pearl shell, in the wild or via human intervention, the shell begins secreting layer of nacre to coat this irritant. Contrary to common myth, the irritant isn’t usually a grain of sand, it’s more likely to be a parasite or piece of tissue.
Over time, layer upon layer of nacre is deposited until a pearl is formed. The pearls that we see on the market today are cultured, meaning that humans have introduced an irritant into the oyster’s shell. When done by human intervention, we refer to this irritant as a nucleus and this process of introducing the nucleus into the oyster is known as seeding.
The process of growing a pearl is a delicate one. The pearl technician is required to spend several years learning the subtle art of inserting a nucleus. Meanwhile, the oyster requires two years to grow from its initial spat stage through to the point where it is ready to receive the nuclei. Once the nucleus has been inserted it takes a further two to three years for a pearl to form.
To ensure that the pearl is of high quality, it is important to carefully monitor the oyster’s progress. If the oyster is not healthy, the pearl will not be either. After a pearl has been formed, the pearl is carefully harvested, cleaned and gently polished. This process can also be quite precarious, whilst nacre is strong and resilient, pearls are amongst the most sensitive gems and should be handled with care to prevent any scratch or damage by contact with sharp objects or exposure to chemicals.
At Broken Bay Pearl Farm, we cultivate Australian Akoya pearls. The pearl shell themselves take years to grow before they’re ready for seeding. After this, the seeding process commences and then another few years later, we can harvest our pearls! Once harvested, our Akoya pearls are gently cleaned.
What is a natural pearl?
Natural pearls are extremely rare. They form in the wild with no human intervention, unlike cultured pearls.
This occurs when a small piece of shell, coral, or other marine debris accidentally finds its way inside the mollusc. In response, the shell secretes nacre to coat the irritant and make it easier to expel. Because the aim is to expel this irritant, the chances of finding a natural pearl are extremely low.
What is a cultured pearl?
Cultured pearls like those grown at our very own Broken Bay Pearl Farm, are very much real pearls. They simply begin their journey with a little help from us.
This help begins with a carefully inserted nucleus into the pearl shell, along with a piece of mantle tissue that helps start the nacre production process. The technique of cultivation was developed in the late 19th century and allows us to grow stunning pearls with Mother Nature still playing a large part in shaping each precious gem
In fact, one of the pioneers of this process in Australia was Lyndon Brown from our sister farm, Cygnet Bay Pearl Farm. He helped develop commercial pearling in the region, and his legacy lives on in the way we farm pearls today and our incredible pearl farm in Australia’s Northwest.
What is nacre?
Nacre, or Mother of Pearl, is the very material that makes pearls shine. It’s composed of calcium carbonate, layered in tiles which gives pearls their iridescence. At Broken Bay Pearl Farm, we often see this stunning layering inside the shells of our Australian Akoya pearl shell, producing that stunning glow that makes pearls and Mother of Pearl so captivating.
Light bouncing of these layers of nacre at different depth causes the shifting rainbow effect also known as lustre.
What colours do pearls come in?
Pearls come in a surprisingly wide range of colours. At Broken Bay Pearl Farm, our Akoya pearl shell produce an array of stunning pearl colours. These can include white, cream, blue, silver, and pink. These variations in colour are dependent on our environment, water temperature, and the oyster’s diet.
Our Australian South Sea pearls, grown at our Cygnet Bay Pearl Farm typically range from white, cream and silver. Tahitian or Black-lip pearls are known for their dark tones, from peacock green to silver grey. Freshwater pearls come in colours like peach, rose and lavender, typically chemically enhanced or dyed for more vivid hues.
Where do pearls come from?
Where a pearl comes from depends on the type of pearl. At Broken Bay Pearl Farm, we grow Australian Akoya pearls just north of Sydney, where the mouth of the lower Hawkesbury River provides perfect conditions to keep our pearl shell healthy.
Our Australian South Sea pearls are grown in northern Western Australia, Indonesia, and the Phillippines. Our sister farm, Cygnet Bay Pearl farm, has been cultivating pearls for almost 80 years on the remote Kimberley coast.
Tahitian pearls are product by the Black-lip pearl shell, in French Polynesia, while Freshwater pearls are cultivated in Chinese lakes and rivers.
What are the different types of pearls?
There are two main different types of pearls which include Saltwater pearls and Freshwater pearls. Saltwater pearls are then categorised into South Sea pearls, Akoya pearls and Tahitian pearls.
What are the Pinctada family of pearl shell?
These are our Saltwater pearl producing pearl shells and as mentioned, include our South Sea, Akoya and Tahitian pearls.
What are South Sea pearls and how are they different?
South Sea pearls are a type of saltwater pearl and are considered the rarest of all types of pearls. They come from the Pinctada maxima shell, where the name “South Sea” originates from the location of the shell, as these shells are found in the southern hemisphere – particularly around northern Australia, Indonesia, the Philippines, Burma and French Polynesia.
Our South Sea pearls are sustainably cultivated in the pristine and remote waters of our Cygnet Bay Pearl Farm, located on the Kimberley Coast, WA.
What are Akoya pearls and how are they different?
An Akoya pearl is a type of saltwater pearl that comes from the Akoya oyster. These oysters are mainly found in the colder waters off the coast of Japan, as well as Vietnam, Korea and Australia. China was a large producer of this pearl type, however, due to several factors, this is no longer the case.
Our Akoya pearls are sustainably cultivated in the lower Hawkesbury, at our Broken Bay Pearl Farm, located on the Central Coast of NSW.
One of the main reasons that so many of the world’s Akoya pearls come from Japan is because it was the Japanese son of a noodle store owner, Kokichi Mikimoto, (perhaps you recognise the surname?) who first learned how to consistently culture pearls. Mikimoto was then instrumental in creating the global cultured pearl industry, a remarkable story and one that we will cover in a future article. While their freshwater cousins average a whopping 20-50 pearls in a single culturing cycle, it would be a rare occasion where an Akoya pearl oyster would produce more than two.
What are Tahitian pearls and how are the different?
Black or Tahitian pearls (Pinctada margaritfera) are synonymous with Tahiti (French Polynesia), although they can also be found in Papua New Guinea, Australia, Cook Islands, Indonesia, India, Japan, Sudan, the Persian Gulf, the Red Sea the Andaman and Nicobar Islands, and several other locations between the tropics.
What are Keshi pearls and how are they different?
Seedless (or Keshi in Japanese) can be found in any location where cultured pearls are farmed and are a beautiful by-product of pearling. Often the result of an unsuccessful seeding, Keshi can be found in the oyster’s reproductive organ and the mantle of the oyster. They usually come in irregular shapes and small sizes and account for under 1% of the total harvest. They are the closest thing to a natural pearl and their relative rarity and often superior lustre can make them more valuable than their nucleated counterparts all other virtues equal.
What are Freshwater pearls and how are they different?
Freshwater pearls are overwhelmingly produced by China; however, this pearl type is the most geographically diverse of all pearl types and used to be found in wild mussels growing in rivers and lakes all over the world until their natural habitats started to be affected by the impact of human population growth.
What are the shapes and sizes of a pearl?
While round pearls are the most iconic, pearls can come in many shapes and sizes, including oval, button, baroque, drop and circle shapes.
The size and shape of a pearl is influenced by the species of the pearl shell, the culturing technique, and the environment in which they are cultivated in.
Our Australian Akoya pearls grown here at Broken Bay usually range in 4-8mm in size, while our Australian South Sea pearls from Cygnet Bay can grow up to 16mm and more! In fact, the largest known gem quality, round, white pearl in the world was harvested from our very own Cygnet Bay Pearl Farm and now happily lives in our Broome Showroom.
How are pearls graded?
Unlike diamonds with a universally accepted scale for grading, different pearl organisations worldwide use different scaling processes to grade the pearls.
Most pearl organisations use the same virtues or value factors to describe and classify pearls:
- Shape,
- Size,
- Colour,
- Surface, and
- Lustre.
Grading systems have been developed to cater to specific pearl types and usually combine lustre and surface to reflect quality as shape, size and colour are considered highly subjective.
The system we use here at Pearls of Australia ranges from B2 to A1 with B2 being the lowest quality and A1 being the highest quality. The other popular way to grade pearls is on a scale from A to AAA with A being the lowest quality and AAA being the highest quality. The factors that are considered when grading pearls are size, shape, colour, lustre, surface quality, and nacre thickness, although this last factor is usually only taken into account when evaluating pearls of the highest quality, and the process to do so often involves using x-ray technology or looking through the drill holes to see where the nucleus and nacre coating meet.
We have created a more in-depth look at the pearl grading process to highlight this crucial stage in the creation of these precious gems.
How do you tell if pearls are real?
The Surface of the Pearl
There are a few things you can do to determine if a pearl is real or not. The first thing you can do is look at the surface of the pearl. A real pearl is more likely to have surface irregularities, unless it’s very expensive, while a fake pearl often has a perfect surface. This means fake pearls will feel much smoother to the touch than real pearls, which have a gritty texture. You can also apply the tooth test to check for grittiness. This involves rubbing the pearl lightly against the front of your tooth. Remember not to rub the pearl against the side of your tooth, as this may scratch the pearl. Again, you’re looking for a gritty texture, which you won’t get if the pearl is fake.
The Colour of the Pearl
The second thing you can do is look at the colour of the pearl. Fake pearls have a uniform colour, so if a pearl is real, what we’re looking for is a translucent overtone that could appear either green or pink over the main colour. Exceptional quality pearls may however have a uniform colour, so this factor should not be used in isolation.
The Shape of the Pearl
The third thing you can do is look at the shape of the pearl. A real pearl can often be misshapen (baroque), so if the pearls you’re examining are perfectly round, and are either at a low price point or are being sold from a less than reputable retailer, then there is a good chance those “pearls” will be fake. Additionally, real pearls are unique in that no two are exactly alike – their shapes and sizes will vary.
The Lustre of the Pearl
Just as we’ve seen with surface, colour and shape, the lustre (the way that the pearls radiate light), also varies with real pearls, while the fake pearls are more likely to radiate light evenly over the entire surface of the pearl. Further, the depth of lustre with real pearls is very pronounced, which gives the sense that the light is radiating from within the pearl. The lustre or lack thereof, of the fake pearls, gives the impression that this effect is shallow and only appears at the surface of the gemstone.
Fake pearls are often created using a process of moulding one of the compounds mentioned above and then coating the surface with a pearl-like substance. As a result, they are not as dense as real pearls and will usually be lighter in weight. Fake pearls may also feel abnormally heavy as they may have been given some additional weight, while the real thing will have a weight that you would have expected it to have.
The Sound of the Pearl
Another way to tell the difference between fake and real pearls is by their sound. Real pearls sound less “tinny” than fake ones, which tend to resonate more hollowly. Another way to differentiate between the two is by how they react to being rubbed. Real pearls will create powder when rubbed while fake pearls will not, however, this activity will cause damage to the surface of the pearl, so we wouldn’t recommend using this as a way of determining pearl authenticity.
The Temperature of the Pearl
The temperature of the pearl can be a good indicator of its authenticity or otherwise. A real pearl will feel cool but will warm up once it’s been in contact with skin. Fake pearls can feel sticky and will be warm even without having been handled.
Want to Learn More About Pearls?
The world of pearls is as fascinating as it is beautiful. From the hands of our skilled pearl technicians, to the pristine environments that our pearls are cultivated in – every pearl has a story. If you’d like to learn more about pearls, we invite you to visit us at Broken Bay Pearl Farm. Join one of our pearl farm tours, or browse our collection of pearl jewellery. We love to share the magic of our work with curious minds and pearl lovers alike.