Why are Black Pearls Black and White Pearls White?

When I thought of pearls, I pictured a perfectly round, glistening, off-white glossy gem growing inside of an oyster. I would have never thought there were so many color ranges and hues when it came to pearls. And I certainly would not have thought there was such a thing as a black pearl!

How are Pearls Formed?

Before we get into what gives pearls their color, and where black pearls come from, we need to understand what exactly a pearl is.

Pearls are formed inside the shell of certain mollusks as a defense mechanism against outside irritants such as parasites. The most valuable and extremely rare pearls are those that occur spontaneously in the wild. Most pearls made for jewelry are cultured or farmed pearls. Cultured pearls a synthetic irritant is introduced to the mollusk in order to produce the pearl inside.

What determines the Color of a Pearl?

The color of the pearl is determined genetically by the host mollusk. Pearl color is also influenced by water conditions, disease, and nutrient supply. Pearls exhibit both a body color, and an overtone. The body color includes white, silver, cream, yellow (golden), gray, or black. The overtone is a soft color over the body color which comes in rose, green, blue, or violet.

Why Black Pearls are Black

Black pearls generally come from the black-lip pearl oyster, and are commonly known as Tahitian pearls. They have become some of the most sought-after, expensive pearls in the world after they were introduced to the world in the mid-1900s by Mr. Robert Wan of Tahiti.

Tahitian pearls are naturally dark in color. However, pure black pearls are rare. These pearls have body colors of silver, grey, and green with overtones ranging from pink to dark green.

What to look for in a Pearl

When shopping for a pearl, don’t just look for the color. Take into consideration the luster, size, and shape of the pearl. Luster refers to the reflective surface of the pearl. A high quality pearl will have an extremely reflective, mirror-like surface.

The average size of a pearl is 8-10.5mm; with the largest size being 23mm. Black pearls are generally larger then white pearls. Finally, the most common shape of a pearl is round, but can also come in a pear-shaped, rice-shaped, baroque, and barrel shaped.

Black Pearls…or White Pearls?

Now that you know where pearls get their color from, which color do you like? White pearls, or black pearls?