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What Is a Pearl?

The way a pearl is created is nothing short of miraculous. Pearls are formed over time when an organic invader burrows deep into the soft tissues of a mollusc. The mollusc then coats the intruder with many layers of natural minerals and proteins, referred to as nacre (Nay-Ker). This is what gives pearls their unique appearance, beautiful lustre and colour. Today, natural pearls are extremely rare, so this process is re-created by oyster farmers who make cultured pearls.

If you’re in the market for pearl jewellery or want to celebrate a June birthday or another special occasion, it’s good to understand the different types of pearls and the factors that determine their value. Pearls come in a number of sizes and shapes, but a classic Akoya cultured pearl strand necklace is the top-seller among our most popular pearl jewellery.

Are Natural Pearls Rare?

The odds of finding natural pearls in the wild are slim—it’s truly a game of chance. Because natural pearls are extremely rare, and the few that are available are exorbitantly priced, Blue Nile does not sell natural pearls. If you do happen to find a natural pearl for sale, it’s good to know that unlike cultured pearls which are graded by millimeters, natural pearls are graded by their carat weight.

Are Cultured Pearls Considered Real?

Although the process used to create a cultured pearl is induced by human intervention, the resulting pearls are every bit as real as the natural ones. Cultured pearls are farmed using one of two types of bivalve mollusc: freshwater river mussels or saltwater pearl mollusks. To create a cultured pearl, a tiny bead and a small piece of mantle tissue are implanted into the oyster to stimulate the production of nacre. We’ll break out the different types of cultured pearls, below.

Quality Factors for Choosing the Right Pearl

The value of a pearl varies widely. While there is no standardized grading system for pearl quality, there are a number of factors that help determine the value of a pearl, including pearl type, size, shape, colour, nacre quality and luster—plus its rarity and weight (for natural pearls) or size (for cultured pearls).

Other factors for assessing the quality of pearl jewellery is how well the pearls match from one to the next. For example, it can take years to produce a strand of South Sea pearls that are all the same millimetre in size, shape and colour, which is why they command a high price.

Types of Pearls and Their Price Points

Natural pearls will always be the most expensive because they are so rare. In the world of cultured pearls, South Sea pearls are the most valuable because of their large size and the fact that they are very difficult to grow. The most highly prized colours of South Sea pearls are golden or pure white. But, they also come in other colours, including silver and blue with green overtones.

pearl types

At Blue Nile, we offer a variety of Freshwater, South Sea, and Tahitian cultured pearls, as well as two individual collections of Akoya cultured pearls. Our pearl jewellery is available in many styles, including studs, fashion earrings, strands, necklaces, pendants, and bracelets. Our pearls come in an array of prices so you can find the perfect ones for your style and budget.

Colour

A pearl’s colour is also called the body colour, presenting in various hues including white, white rosé, black, silver, gold or pink. A pearl can also have a secondary overtone, which is seen when light reflects off the pearl’s surface. For example, a pearl strand may appear white at first glance, but a closer look may reveal a translucent overtone that’s rose, green or blue.

Pearl Colour

Lustre

Pearls produce an intense, deep shine called lustre. This is a combination of the pearl's exterior shine and glow from within, created by light reflected from the calcium carbonate crystals that make up the pearl's nacre. Lustre is determined by the nacre's thickness, degree of translucence, and arrangement of layers. These factors vary depending on the type of pearl and how long it’s allowed to grow. Contrary to popular belief, a pearl’s nacre is not related to its size. A tiny Akoya pearl may have amazing lustre, while a large one that’s harvested too early, would be very dull.

Shapes

There are three main pearl shapes: spherical, symmetrical, and baroque or non-symmetrical. The basic pearl shapes fall within those categories like this:

Spherical

  • Round
  • Near-round

Symmetrical

  • Oval
  • Button
  • Drop
  • Teardrop

Baroque (Non-Symmetrical)

  • Semi-baroque
  • Baroque

Surface Markings

As a mollusc creates a pearl, the layers of nacre do not always adhere smoothly. Sometimes spots and bubbles, called surface markings, can appear in the layering process. Pearls with the smoothest surfaces are the highest-quality, and the most sought-after—and they come with a price tag to match.

Treatments

There are several gem treatments commonly used to enhance a pearl’s beauty. It safe to assume that every Akoya pearl has been bleached to remove dark spots and create a more uniform colour. This treatment may also include irradiation and dyeing. Dye is used to create many different hues, particularly with freshwater species. Irradiation is another method used to change a pearl’s natural colour.

Size

The size of a pearl greatly depends on the type. Cultured freshwater pearls range in size from about 3.0–13.0mm, Akoya pearls range from about 6.0–8.5mm, and South Sea and Tahitian pearls can reach sizes as large as 13mm. Of course, with an ideal environment and conditions, natural pearls can grow to be much larger.

How to Identify Real vs. Fake Pearls

The biggest difference between real and fake pearls comes down to their surface feel. The surface feel of real pearls is slightly uneven, while the surface of plastic or glass beads is perfectly smooth. Because pearls are made by nature (or cultured to mimic the natural process), real pearls will also vary slightly in size, colour and lustre compared to the uniform look of fake pearls.

Pearl Care

The top rule for pearls is that they should be the last thing you put on and the first thing you take off. Their lustre can be dulled by hairspray, lotion and perfume. Wear them often and your body’s natural oils will keep them lustrous. Before putting them away, wipe them with a soft cloth. Store them apart from other harder jewellery to keep them from getting scratched. As an organic gem, pearls need to breathe. So, it’s best if they’re stored in a soft bag, not plastic.

If worn routinely, it’s recommended to restring a pearl strand or bracelet every five years, or if you see discoloration or fraying. Pearl strands that are tightly strung can sometimes be loosened by hanging them on a door knob in a bathroom, where the weight of the pearls and the moisture in the room help to straighten the strands out.

Pearls are glued to earring posts through an epoxy process. Occasionally they detach from the post. Don’t worry! Our experts will be happy to assist you with shipping them back for repair.

Next: Learn more about our most popular type of pearl

Have A Question?

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