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Interesting Facts about Pearls - Formation and Types of Pearls

A Botany graduate, Nithya Venkat enjoys researching and writing about topics that interest her.


Pearls are precious, highly valued gems that have a lustrous shine and come in different colors and hues. Pearls are produced by oysters and by other shelled mollusks such as clams and mussels. Pearls start forming when mollusks react to the entry of a foreign particle into their shell.

There are freshwater pearls and saltwater pearls. Freshwater pearls are made by mussels that live in freshwater lakes and rivers. Freshwater pearls come in different shapes and forms. They are naturally white, cream, pink, peach or lavender in color.

Saltwater pearls are made by saltwater clams that are also known as "Pearl Oysters." They are round and have a better shine when compared to freshwater pearls. Saltwater pearls are naturally white, cream, yellowish golden or silver gray in color.

How do pearls form?

The body of the oyster is protected by a shell that is made up of two parts joined by a hinge. The body is separated from the shell by a layer called the "mantle." The mantle secretes a substance called, "nacre" that hardens to form the outer layer of the cell.

The formation of a pearl is initiated when a foreign particle is trapped between the mantle and the innermost layer of the shell. When this happens, the particle irritates the mantle layer. To soothe this irritation, the oyster produces a substance called "nacre" around the foreign particle starting the formation of a pearl.

A pearl is a foreign particle entirely covered with nacre. All pearls are not round. Some pearls have uneven shapes and are known a "baroque" pearls.

How do pearls form?

How do pearls form?

Cultured Pearls

Cultured pearls are made by the intervention of humans. To create a cultured pearl, the shell of the oyster is opened, and a small part of the mantle is slit open. A small particle is inserted into the mantle and the innermost layer of the shell. This particle acts as the irritant.

The oyster treats this irritation by secreting nacre around the particle and over time this becomes a cultured pearl. Cultured pearls are not as expensive as natural pearls.

Akoya Pearls

Akoya pearls are truly classic pearls that are round and are almost smooth. They have very few imperfections or no imperfections at all. They have the highest lustre and shine when compared to other pearls. These pearls are white or cream in color.

Tahitian Pearls

Tahitian Pearls

Tahitian Pearls

Tahitian Pearls are grown in the Black-Lipped Oyster. These pearls are black in color and are large ranging from 9 mm–16 mm in size.

Tahitian Pearls come in a wide range of colors such as black, grey, silver, green, blue and purple.

South Sea PEarls

South Sea PEarls

South Sea Pearls

South Sea Pearls are saltwater pearls that are cultivated from the oysters living in the South Seas near Northern Australia and South-East Asia including Myanmar and Indonesia. They produce pearls that are 10 - 20 mm in size and are silver or gold in color. These pearls are the largest of cultivated pearls and the most expensive ones.

Keshi Pearls

Keshi Pearls

Keshi Pearls

Keshi Pearls are rare freshwater pearls and are fully made of nacre. These pearls are not round. These pearls do not have the particle (also referred to as the nucleus of the pearl) that acts as an irritant. Keshi Pearls come in different shapes, sizes, and colors.

In the case of Keshi Pearls the particle (nucleus) that acts as an irritant is pushed out of the mollusk but the pearl formation continues. Due to the absence of a central nucleus, the entire pearl is made of nacre.

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Coin Pearls

Coin Pearls

Coin Pearls

Coin pearls have a flat surface just like coins and are freshwater pearls. The flat surface of the pearl allows more light to reflect off the surface of the pearl. This results in the pearl having a greater shine when compared to other pearls.

How to take care of pearls?

Do not keep pearls with other jewellery, store them in a soft cloth pouch.

Do not store pearls in a plastic bags because the chemical in the plastic can discolour the pearls.

Store pearl jewelry on a flat surface.

Do not spray perfumes or deodorants directly over the pearls.

Do not use strong detergents to clean pearls.

Clean pearls with a soft damp cloth to wipe them, use another soft dry cloth to wipe away the moisture.

Do not wear pearls after applying any medicated cream on your skin.

More Facts about Pearls

Pearls are the only gems made by animals during their lifetime.

Harvesting pearls do not kill mollusks.

The nacre layer alone is referred to as the "Mother of Pearl".

All mollusks can make pearls.

Pearls get their color from the shell in which they grow.

Akoya or saltwater pearls are made by oysters and can take five to twenty years to grow.

Freshwater pearls are produced by mussels and can take one to six years to grow.

Every pearl is unique, and all pearls have minor imperfections.

Today mostly all pearls are cultivated.

Pearl farming is known as “Periculture.”

The oldest pearl was found in the sarcophagus of a Persian princess; it is currently displayed in the Louvre Museum in Paris.

Legends state that Cleopatra dissolved a pearl in wine and drank it to prove her love for Marc Antony.


Know what you are buying

© 2014 Nithya Venkat


Nithya Venkat (author) from Dubai on January 11, 2020:

Thank you Donna Rayne.

Donna Rayne from Sparks, NV on January 07, 2020:

I really enjoyed your article, it was interesting and informing. Thank you for sharing your excellent work! I learned a lot!


Donna Rayne

Nithya Venkat (author) from Dubai on January 07, 2020:

Thank you Naomi's Banner for your visit and comment.

Naomi's Banner from United States on January 07, 2020:

Wow, very good article! Love the pics. This is interesting and informative at the same time. Thanks for writing this article!

Nithya Venkat (author) from Dubai on August 05, 2015:

frogyfish thank you for reading and leaving an insightful comment, much appreciated.

frogyfish from Central United States of America on August 02, 2015:

I enjoyed learning about these lovely 'gems', and appreciated the fact that the shell-life did not have to be killed to remove pearls. Your expertise about grading pearls was informative and the video interesting too. Thanks for a light and interesting article.

Nithya Venkat (author) from Dubai on April 27, 2015:

tillsontitan thank you for reading and am glad you came to know about pearls that are fascinating and beautiful! Thank you for the many votes too, much appreciated.

Mary Craig from New York on April 26, 2015:

What a great education about pearls! I had no idea there were so many varieties nor did I realize how long some can take to form. We see movies and just take things for granted.

Your tips on care are certainly useful as well.

Voted up, useful, awesome, and interesting.

Nithya Venkat (author) from Dubai on May 01, 2014:

Hady Chahine thank you for reading. Watch the video that will answer your question.

Hady Chahine from Manhattan Beach on April 30, 2014:

How do you tell the difference between a natural vs. cultured pearl? I ask because over the years I've handled several pearl necklaces but never once did I think to ask the question.

Nithya Venkat (author) from Dubai on April 30, 2014:

rajan jolly thank you, freshwater pearl mussels produce many pearls at one time, I do not know the exact number, will find out. Fresh water pearl farmers can nucleate a mollusk with up to 32 pieces of mantle tissue at one time. In such a case the mollusk will produce 32 pearls. Thank you for the vote and share.

Rajan Singh Jolly from From Mumbai, presently in Jalandhar, INDIA. on April 30, 2014:

Very interesting. I believe pearls are so expensive as it takes a long time for it to be formed.

By the way how many pearls can a mollusk or oyster make at one time?

Voted up, interesting and shared.

Nithya Venkat (author) from Dubai on April 13, 2014:

vocalcoach you are so right, pearls are really beautiful. Am glad you enjoyed my hub. Thank you for reading. Hugs right back to you.

MG Singh am sure your girl friend must love them, thank you for reading.

MG Singh from UAE on April 13, 2014:

Thanks for the information. i like to present pearls to my girl friend.

Audrey Hunt from Pahrump NV on April 12, 2014:

There is something about pearls - timeless beauty is what I call them. And so is this hub. I enjoyed the "facts" you presented as well as "how to care for pearls."

Thank you so much, Vellur, for the valuable information. So well presented! Hugs - Audrey

Nithya Venkat (author) from Dubai on March 13, 2014:

AudreyHowitt thank you, pearls are beautiful!

Audrey Howitt from California on March 13, 2014:

I love pearls, especially the ones that are not cultured--but come in unusual shapes and colors--really a wonderful article on the subject

Nithya Venkat (author) from Dubai on February 12, 2014:

Lady E thank you for your visit, much appreciated.

Elena from London, UK on February 11, 2014:

A "must read" for every woman. :-) Thanks

Nithya Venkat (author) from Dubai on January 29, 2014:

rdsparrowriter thank you for your visit. Thanks for the vote too.

Rochelle Ann De Zoysa from Moratuwa, Sri Lanka on January 28, 2014:

It's very interesting and I learnt a lot by reading your beautiful hub :) A surprised pain turns into a very valuable gem.... Voted up and useful :)

Nithya Venkat (author) from Dubai on January 28, 2014:

Eiddwen thank you for your visit. Thanks for the vote and share.

Eiddwen from Wales on January 28, 2014:

A very interesting read and thanks for sharing Vellur.

Voted up and shared.


Nithya Venkat (author) from Dubai on January 22, 2014:

stuff4kids thank you and am glad you found my hub fascinating.

b.Malin thank you, pearls are beautiful. Thank you for stopping by.

b. Malin on January 21, 2014:

What a Wonderful and most Educational read Vellur. I Love my Pearls...and now I know the how's and why's...Thank YOU!

Amanda Littlejohn on January 21, 2014:

How interesting. I've learned a great deal here today.

I had no idea how many different kinds of pearls there are and perhaps even less about the details of how they form.

Fascinating and educational. Thanks for sharing. :)

Nithya Venkat (author) from Dubai on January 20, 2014:

MartieCoetser thank you for stopping by. As far as I know, if the oysters are not killed for eating purposes a plug is placed between the shells and the pearl is gently removed using tweezers.

Martie Coetser from South Africa on January 19, 2014:

This is a very interesting and comprehensive hub about the formation of pearls. Thank you, Vellur! All of a sudden I am extremely curious to know exactly how pearls are harvest without killing mollusks or mussels.

Nithya Venkat (author) from Dubai on January 19, 2014:

DDE thank you for stopping by, pearls are gorgeous.

Devika Primić from Dubrovnik, Croatia on January 19, 2014:

What are pearls? How do pearls form? Types of pearls is a very interesting and informative hub about pearl it never crossed mind until now about pearls you have created a helpful hub on this topic with beautiful photos. The different kinds are extravagant.

Nithya Venkat (author) from Dubai on January 18, 2014:

Faith Reaper yes you said it, they are classy and beautiful. Thank you for the visit and share.

Nell Rose I do hope you find many Tahitian pearls, thank you for stopping by.

always exploring, Akoya pearls are beautiful. Jackie Kennedy was beautiful and she wore pearls with style. Thank you for stopping by.

tirelesstraveler great to see you too! Pearls are in style and are great to wear for any occasion. Thank you for stopping by.

Judy Specht from California on January 18, 2014:

I was so excited to see you tonight Vellur.

This is very informational hub. Pearls seem to be coming back into style. I will go examine the two strands I own, with the knowledge you have equipped me with.

Ruby Jean Richert from Southern Illinois on January 18, 2014:

I was unaware of the different kinds of pearls. I especially like the akoya. I never owned any pearls, although i think they are beautiful. When i think of pearls i remember Jackie Kennedy, she loved them. Very interesting the making of pearls, fascinating really. Thank you....

Nell Rose from England on January 18, 2014:

Hi Vellur, this was fascinating reading, and my favorite has to be the Tahitian Pearls, they are gorgeous! wish I could find one, great hub!

Faith Reaper from southern USA on January 18, 2014:

I love pearls too. They are so classy and beautiful. All girls need a pearl necklace. Awesome article and interesting as to how they are formed. Up and more and sharing. Blessings, Faith Reapet

Nithya Venkat (author) from Dubai on January 18, 2014:

Jackie yes pearls are more beautiful than diamonds, pearl earrings look awesome. Thank you for stopping by.

billybuc there is a great demand for pearls, cultivated pearls are less expensive than natural ones. Thank you for reading.

Bill Holland from Olympia, WA on January 18, 2014:

Very interesting. I agree with Jackie, I think they are more beautiful than diamonds. I have always wondered why they are so expensive since they are renewable and there is no shortage of them....I guess demand dictates that.

Jackie Lynnley from the beautiful south on January 18, 2014:

Pearls are more beautiful than diamonds to me and there is just a purity about them. I am not much for jewelry other than small earrings since my ears are pierced but I will wear pearls and those black ones are gorgeous! ^

Nithya Venkat (author) from Dubai on January 18, 2014:

teaches12345 thank you, pearls are great to wear for any occasion. Taking proper care of pearls will help to keep the shine longer.

Dianna Mendez on January 18, 2014:

I do love pearls. Your section on care is great and more than the jeweler gave me at purchase. Quite an interesting post.

Nithya Venkat (author) from Dubai on January 18, 2014:

Sunshine625 I do hope you find a big pearl one day. Thank you for stopping by.

Linda Bilyeu from Orlando, FL on January 18, 2014:

Awesome article about pearls! We eat mussels often and hope to one day find a pearl or two :)

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