How to Buy a Pearl Necklace

With nearly 70 years in the business, we know everything there is to know about pearl jewelry, from sourcing premium pearls to helping our customers get the perfect item. In this guide, you'll find helpful information about grading, standard pearl necklace lengths as well as a pearl millimeter chart to help you visualize the size of the pearls before you buy.

The Pearl Grading System

According to their website and recognized throughout the world, "GIA uses a comprehensive standard it developed over a 70-year period of ground-breaking research on pearls, called The GIA 7 Pearl Value Factors™ (Size, Shape, Color, Luster, Surface, Nacre, and Matching).The GIA 7 Pearl Value Factors™ provide a systematic way to evaluate pearls of all types, and to describe their appearance and quality in a way everyone can understand." Each product on American Pearl's website has a table below it that describes the GIA 7 Pearl Value Factors for your convenience.

Pearl Types used in GIA Grading

In addition to pearl sizing and pearl grading, it is important to learn about the different Pearl Necklace Styles to help you with your purchase (For example, Single Strands, Double Strand, Long Strands, etc...). You can learn more about pearl necklace styles by watching the video below:

Measuring Pearl Necklace Sizes

Japanese Akoya Cultured Pearl Necklaces are measured in half-millimeter increments. For example, a necklace may be 7mm x 7.5mm or another may be an 8mm x 8.5mm where the pearls measure from 7mm on either end of the necklace and slowly graduate to 7.5mm in the necklace's largest center pearl. Even though these necklaces have this slight range of graduation, they are considered to be Uniform Pearl Necklaces. Other necklaces that have more than a half-millimeter range of graduation are considered to be Graduated Pearl Necklaces. In order to complete a pearl necklace where all the pearls have a similar shape, color and quality pearl companies need this half-millimeter range to ensure all the pearls match. After all, matching a full necklace of pearls that all have the same size, color and quality is challenging. Most consumers are looking to purchase either a (1) Uniform pearl necklace or a (2) graduated pearl necklace. In the two comparison charts below, one can see the difference between uniform and graduated pearl necklaces.

Uniform Pearl Necklaces (the most popular)

Uniform Japanese Akoya Pearl Necklace Graduating from 7mm to 7.5mm

Japanese Akoya Pearl Necklace Graduating from 7mm to 7.5mm

Graduated Pearl Necklaces

Graduated Japanese Akoya Pearl Necklace from 3.5mm to 7.5mm

Graduating Japanese Akoya Pearl Necklace from 3.5mm to 7.5mm

Akoya Necklace Millimeter Size Chart

Japanese Akoya Cultured Pearls from 5.5mm to 10mm Size Chart

Japanese Akoya Pearl Sizes From 5.5mm to 10mm next to a Dime

5.5mm x 6mm Akoya Cultured Pearl Necklaces

5.5 x 6mm Pearl Necklace Next to Ruler

5.5 x 6mm Pearl Necklace - Priced from $250 up to $850
Generally for young teens, 12 to 16 years. This is our smallest-diameter pearl readily available for stringing. It is usually bought for young teens but may also be appropriate for an extremely petite woman or if she specifically requested this size. It is very popular for teenagers for Christmas, birthdays, and school-related and coming-of-age occasions, especially confirmations, bat mitzvahs and Sweet Sixteens.

5.5 x 6mm Pearl Necklace Size

6mm x 6.5mm Akoya Cultured Pearl Necklaces

6 x 6.5mm Pearl Necklace Next to Ruler

6 x 6.5mm Pearl Necklace - Priced from $450 up to $950
Generally for older teens and young women, 16 to 24 years. This size more or less follows the same guidelines as for 5.5 x 6mm (above), except that it is generally bought for older girls who are closer to their adult height.

6 x 6.5mm Pearl Necklace Size

6.5mm x Akoya Cultured Pearl Necklaces

6.5 x 7mmm Pearl Necklace Next to Ruler

6.5 x 7mm Pearl Necklace - Priced from $725 up to $1290
Generally for 25 to 30 year olds. Similar to 6mm x 6.5mm except she is less likely to outgrow this pearl necklace until she is in her early thirties.

6.5 x 7mm Pearl Necklace Size

7mm x 7.5mm Akoya Cultured Pearl Necklaces

7 x 7.5mm Pearl Necklace Next to Ruler

7 x 7.5mm Pearl Necklace - Priced from $690 up to $1500
Generally for younger women 30 and up. This is the best size for a starter necklace for a younger woman. It's the necklace she wears for her first day of work as a career woman. Likewise, 7mm pearl earrings (actual size) would be perfect for starting a new job. It's very popular as a college graduation gift and a wedding-day gift from the groom, and is also great for new mothers and just about any worthy occasion in a young woman's life: Valentine's Day, Secretary's Day, Mother's Day, a baby shower, or a "just to say I love you" present.

7 x 7.5mm Pearl Necklace Size

7.5mm x 8mm Akoya Cultured Pearl Necklaces

7.5 x 8mm Pearl Necklace Next to Ruler

7.5 x 8mm Pearl Necklace - Priced from $990 up to $1590
Generally for women 30 and up. This is the last size in the lower bracket of more readily available sizes; a jump to the next size, 8 x 8.5mm, more or less doubles the strand's price. It's really the only size one could call neither "too small" nor "too big." It's a staple of any woman's wardrobe; she can dress it up or dress it down. It's not too showy, and it very tastefully exudes an image of importance, making it a classic for the upwardly mobile career woman. It also suits very well as a wedding-day gift or a wedding anniversary gift through the fifth year of marriage.

7.5 x 8mm Pearl Necklace Size

8mm x 8.5mm Akoya Cultured Pearl Necklaces

8 x 8.5mm Pearl Necklace Next to Ruler

8 x 8.5mm Pearl Necklace - Priced from $1490 up to $2750
Generally for women 35 and up. A classic strand that nicely straddles the rarity brackets because it's the first size of the larger, rarer harvests. So it says "I jumped to the next price tier" without actually jumping too exorbitantly. From here on up, the prices climb much more steeply than they do through the much more common first five sizes. Anything larger than those has to stay in the waters twice as long to have a shot at growing that large. The sizes from 8 x 8.5mm up therefore become exponentially harder to harvest, therefore exponentially rarer and more valuable. This size is more important-looking and expensive-looking than 7.5 x 8mm; it screams "successful woman here!" It can be worn with everyday wear yet also looks the part at a black-tie event, where a 7.5 x 8mm might look somewhat skimpy. Similarly, 8-9mm pearl earrings (actual size) are just right for this stage of life between just starting out and entering her senior years. It also makes for a good strand for collectors and investors; the doubly long submergence serves to protect the pearls' price and gives them the best chance to appreciate in value over time.

8 x 8.5mm Pearl Necklace Size

8.5mm x 9mm Akoya Cultured Pearl Necklaces

8.5 x 9mm Pearl Necklace Next to Ruler

8.5 x 9mm Pearl Necklace - Priced from $1750 up to $4100
Generally for women, 37 to 45 years or extremely successful 30s. The Porsche of pearls. A power strand that's elegant, classy and chic. It's the Rolex Daytona of pearls in that they are among the most difficult pearls in the world to get your hands on but are still attainable. This strand is plainly recognizable as among the more expensive breed and thus projects power, strength and stability. It makes for the perfect choker for senior-management corporate culture while doubling very nicely as an evening piece for a black-tie event. These are sure to be deeply appreciated by a sophisticated woman who loves and knows her pearls. A double strand of these is what Jackie Onassis typically wore.

8.5 x 9mm Pearl Necklace Size

9mm x 9.5mm Akoya Cultured Pearl Necklaces

8.5 x 9mm Pearl Necklace Next to Ruler

9 x 9.5mm Pearl Necklace - Priced from $2200 up to $10,000
Generally for women, 45 years and up or extremely successful 30s. The Ferrari of pearls and the CEO's strand. Simply regal and extremely rare. For a refined, discriminating woman who is serious about her pearls and won't settle for anything but the best. Also a solid choice for a woman on her way into upper management who now needs to notch it up over her well-worn 7.5 x 8mm strand. The second-rarest size, it makes for a strand that is sure to be very hip and stylish in any social bracket; her friends won't stop talking about it (you'll score big points for this!). It is usually purchased as a versatile double-strand choker (18 inches) that can be converted into a single-strand opera (36 inches).

9.5mm x 10mm Akoya Cultured Pearl Necklaces

9.5 x 10mm Pearl Necklace Next to Ruler

9.5 x 10mm Pearl Necklace - Priced from $6000 up to $24,000
Generally for women 45 years and up or extremely successful 30s. The Lamborghini of pearls. Absolutely majestic, fit for a queen. The rarest size of all, virtually impossible to get; Japanese cultured pearls simply don't grow any larger than this. A guaranteed grand slam for Mother's Day, Christmas or any event for the elegant elderly woman. Made most famous by Barbara Bush who was often seen with her pearls of this size coiled around her neck. Usually purchased as a double strand (36 inches).

But there is indeed a difference between sizes. In fact, there is actually a hierarchy of meaning assigned to the different sizes: in much the same way that different rose colors mean different emotions and anniversaries have "traditional" gifts, pearl sizes correspond to traditional ages and occasions. As with roses and anniversaries, these are traditional "criteria" which are not always followed in practice. However, one should be aware that since pearl purchases are infrequent relative to roses and anniversaries, the criteria have been more resistant to change over the years, and therefore remain relatively widely accepted for most pearl-buying occasions. What preceded was a breakdown of the various sizes along with their respective general age brackets and significance. We say "general" age brackets because as you will see the brackets are non-binding, since the meaning of the pearl size does not always hinge on age alone. However, it is generally advisable to remain within one pearl size on either side of the age bracket. In other words, you would not want to buy a 45-year-old woman the smallest pearl size, which is generally worn by younger teens. Conversely, a too-large size would look too big and ungainly on the neck of a 14-year-old and might make her look like she's too young to be wearing pearls.