Fact Checked

Where do Black Pearls Come from?

Brendan McGuigan
Brendan McGuigan

Pearls are formed by many mollusks as part of a natural process to lessen the effect of irritating debris. When a small piece of particulate matter becomes trapped inside the mollusk, calcium carbonate is deposited on its surface, and over time this calcium carbonate (called nacre) forms a pearl. Black pearls are made by a species of oyster called Pinctada margaritifera, commonly known as the black-lipped oyster.

Many bivalves generate pearls, and most are desirable for jewelry. Of the mollusks which create pearls, including abalone and mussels, the pearls created by oysters are the most sought after. These pearls may come in a variety of different colors and degrees of quality, depending on the species of oyster, the seed object, and a number of other variables.

Most pearls are cream or white in color.
Most pearls are cream or white in color.

The Pinctada margaritifera oyster appears in the South Pacific. Historically, most black pearls came from Tahiti, and they are therefore known as Tahitian black pearls. In recent years, however, both nearby Kiribati and the Cook Islands have begun producing these pearls, accounting for 3-4% of the world's supply.

In the past, black pearls were amazingly expensive due to their extreme rarity. Approximately one in ten-thousand oysters produces a pearl that is black, and of these, a small fraction are of adequate luster, shape and size to be desirable. They are, therefore, associated with high luxury and class in jewelry, and many prestigious necklaces and bracelets of royalty and the elite contain ones of large size.

Black pearls are extremely rare, and therefore expensive.
Black pearls are extremely rare, and therefore expensive.

Since the 1960s, black pearls have been cultured, causing a dramatic decrease in price. A piece of Mississippi freshwater clam shell is used as a nucleus, placed near the oyster's genitals, along with a bit of flesh from the oyster to serve as a mantle. Over approximately the next two years, the oyster places thousands of layers of nacre and ultimately creates a pearl.

Tahiti's economy relies on tourism and the export of black pearls and other products.
Tahiti's economy relies on tourism and the export of black pearls and other products.

These pearls are substantially larger on average than their more common white brethren. Most white (and off-white) pearls come from the Japanese Akoya oyster, which rarely exceeds 3 inches (7.6cm) in diameter. Pinctada margaritifera can exceed 1 foot (30.4 cm) in diameter, allowing for pearls in excess of 0.5 in (12 mm).

Black pearls, it should be noted, are rarely actually black in color. They range from nearly black to white, and many are silver, but the rarest and most valuable are a deep purplish green. The luster of a pearl is also a major factor in its apparent color, with the best pearls having a translucent sheen that reflects a number of different colors, depending on the angle from which it is viewed.

Although harvesting natural oysters for pearls in places like Tahiti is illegal, with the advent of cultured black pearls, prices have become more affordable for these rare beauties. Even the smallest of such pearls are certain to draw attention and praise from all who see them, and they are often a wonderful addition to a special piece of jewelry.

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Discussion Comments


@Kristee – There are a couple of ways. One is to rub the pearl across your teeth. If the pearl feels smooth, it's fake, but if it feels gritty, it's real.

Another way is by how heavy it feels. Lots of fake ones are made of plastic, so they are light. Real ones are heavy, but so are pearls made of glass, so this isn't the most reliable way to tell.

Fake pearls are pretty cheap. Vendors don't usually try to sell fake ones at the prices that real ones could fetch, because they know that experts could expose them.


There is a vendor selling loose black pearls at the monthly arts and crafts fair in my town. I have no idea whether they are real or fake, though.

How can you tell a real black pearl apart from a fake one? Is there a way to distinguish between the two without destroying the pearl?


Natural black pearls are so lovely. My grandmother gave me a black pearl necklace as a graduation gift, and she also included a separate white pearl in the box.

The pendant had a silver teardrop shape surrounding the black pearl. I could open it and switch out the black pearl with the white one whenever I wanted.

I know that they had to be very expensive. However, my grandmother had inherited a small fortune when her father-in-law had passed away, and I'm glad she chose to spend such a big chunk of it on my graduation gift!


@burcinc – I find it sad that oysters are basically tortured so that manufacturers can make and sell black pearl jewelry. If this happens in the wild, it's perfectly acceptable, but purposely irritating a living thing in order to make money is unethical in my eyes.

I have no problem with harvesting black pearls from nature. I just take issue with causing oysters pain on purpose.


@alisha-- Yes, that's right.

Have you ever seen the inside of a shell? Usually, the inside of seashells are shiny, iridescent and smooth. That layer is called a nacre. This is the same layer that exists on pearls that is largely responsible for the color of the pearl and it is made of calcium carbonate. So a black-lipped oyster will produce dark hued nacre which will result in a black pearl.

There are also other factors that influence the color of the pearl, like the quality of the water, how deep the oyster is in the water and so forth. That's why there are different shades of black pearls, some have a grayish tone to it for example while others have purplish or greenish tones to them. I have a black pearl necklace with purple tones that is just gorgeous.


So is this kind of pearl black because the oyster deposits black colored calcium carbonate?

I still don't understand how the pearl comes out black.


@aaaCookie-- I knew there were black pearls, I have seen jewelry made with them in the mall. But I thought that they made them by taking white pearls and coloring them black. How cool is it that oysters actually make black pearls!

But do you guys think that culturing black pearls, or any pearls for that matter, is ethical?


When the movie "the Curse of the Black Pearl" came out, I just thought the name was supposed to be creepy or mysterious. I didn't realize that there were actual black pearls. Thinking of how rare they are, the title of that film makes more sense now.


Pearls are mostly out of style these days, I think because the classic pearl necklace look has just been done so many times. If I could afford it, though, I would love a similarly styled necklace of black pearls. They just give such a different, unexpected look than ordinary pearls.

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    • Most pearls are cream or white in color.
      By: valeriy555
      Most pearls are cream or white in color.
    • Black pearls are extremely rare, and therefore expensive.
      By: teena137
      Black pearls are extremely rare, and therefore expensive.
    • Tahiti's economy relies on tourism and the export of black pearls and other products.
      By: lulu
      Tahiti's economy relies on tourism and the export of black pearls and other products.