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Pearl Value Factors

It is Week 3 of the month with the best birthstone, Pearl. With every pearl being created by an individual organism, affected by various environmental conditions, quality of care, culturing time, and overall health of the mollusk, every pearl needs to be evaluated individually. So how do we evaluate pearls?

This week, let's take a look at the Pearl Value Factors and the nuances that go into determining a great pearl from a good pearl from a nasty pearl. There is no universal system for evaluating pearls like there is with diamonds, but by using these guiding principles, we can consider each pearl and create beautiful jewelry.

#1: Size

Pearl size refers to the diameter dimension of the pearl and it is expressed in millimeters (mm).

It doesn't matter what they told you: Size Matters. All other value factors being equal, a larger pearl will be more valuable.

Pearl size is dependent on several factors:

  1. The mollusk species—some mollusks can grow larger pearl than others

  2. The size & health of the mollusk (Bigger/Better = Bigger)

  3. The size of the bead nucleus (Bigger = Bigger)

  4. Length of time the mollusk stays underwater (Longer = Bigger)

  5. Climate and nutrient conditions of the growing environment (Consistently Good = Bigger)

Pearl Size Chart

#2: Shape

The pearl shape is the silhouette of the pearl, which ranges from round to baroque. There are three distinct shape categories: Spherical, Symmetrical, and Baroque.

For any shape other than the three major categories, the shape is described as it appears (coin, stick, button, etc).

A pearls shape is dependent on several factors:

  1. The shape of the bead nucleus

  2. Length of time the mollusk stays in water (Longer = Less predictable and less round)

  3. Climate and nutrient conditions of the growing environment

The longer the pearl remains within the mollusk, the greater the chance of developing an irregular shape. A perfectly round pearl is very rare. Even if the bead nucleus is round, the pearl may not grow evenly in all directions. A large, perfectly round pearl is even rarer!

Pearl Shape Chart

#3: Color

Pearls come in a wide range of colors resultant of the breed of the host mollusk and that of the donor tissue. The pearl will likely be similar in color to the mother-of-pearl lip of the mollusk in which it forms. There are a host of external influences, including diet, water temperature and pollutants., that can effect the color of the pearl, making it impossible to accurately predict the color of the pearl.

Pearl color is a combination of three elements:

Body colors: Body color is the dominant hue of a pearl. What color do you see when you just glance at the pearl? Overtones: Translucent color that overlies bodycolor. If you tilt the pearl from side to side and squint, is there a slight tinge of a secondary color? Orient: Iridescent rainbow colors on the surface. This is the magical, rainbow wash you see when you look at a pearl.

All pearls have a body color, but not every pearl displays overtone and/or orient.

#4: Luster

Luster is what pearls do best. Luster is the way the light plays off of the surface of the pearl. Due to the pearls' nacre structure, light does not just reflect off of the surface of the pearl. Rather, light penetrates the surface and seems to reflect from WITHIN the pearl. The way that a pearl seems to emit light is its luster.

The quality of the nacre dictates the quality of the luster, which is very important to its beauty and its value. Pearl farmers can control the quality of nacre only to an extent. For example, allowing the pearl to form for more time will tend to make the nacre thicker and harvesting pearls during cold weather can often improve final luster quality! Many environmental factors can interrupt or alter the nacre formation, so there is no fool-proof method for creating a beautiful luster.

Pearl Luster

#5: Surface Complexion

Like other gemstones, pearls have clarity characteristics, but since pearls are not transparent or translucent, clarity is confined to the surface as blemishes in the surface complexion. Surface complexion is defined by the degree and visibility of surface imperfections. The fewer blemishes, the better the surface complexion.

Pearl blemishes that are often seen include: Pits, Abrasions, Bumps, Ridges, Chips, Cracks, Flat areas, spots, or uneven nacre coating.

Surface complexion is categorized using the terms: clean, lightly blemished, moderately blemished, heavily blemished.

A spotless pearl is extremely rare and valuable. If, for example, a pearl is large with excellent luster, these qualities will outweigh minor surface imperfections. Large or numerous imperfections not only lower the value, but can affect durability and the ability to see a pearl’s luster as well.

Pearl Surface Complexion

#6: Nacre Quality

The only way to determine the exact thickness of the nacre is to x-ray the pearl or cut it in half (I don't recommend cutting your pearls in half!). However, there are ways that we can visually assess the nacre quality. With careful examination, the nacre thickness can at times be visible through the pearl’s drill hole. With thin nacre, it may be possible to see the bead nucleus through the surface, which will be very chalky or dull as a result, lacking luster.

The longer the cultured pearl is allowed to remain in the oyster, the thicker the nacre coating will be. However, the longer the pearl remains in the oyster, the greater the chance of blemishes or misshapen pearls.

Pearl Nacre Thickness

#7: Make

Make is the human artistry that goes into assembling a final piece of jewelry. This is the moment when a maker considers the above factors, combining them in an interesting way to lead to a beautiful make. Here is how that works:

  1. Size: In a single strand, pearls are often matched to have the same diameter size. Matching for size could also mean that the strand displays an even graduation between sizes

  2. Shape: Pearls come in a variety of shapes. By choosing consistently shaped pearls, we match for shape.

  3. Color: Matching for color can be complex. You can match pearls for their same body color, overtone, and orient. OR, you can intentionally mismatch colors, while keeping other factors the same for continuity throughout a piece!

  4. Luster: When pearls display matched luster throughout a piece, light reflects evenly across the the entire piece of jewelry. This creates a harmonious effect.

  5. Surface Complexion: Pearls are matched in terms of the quality of their surface complexion. In the industry, you will often see pearls with more blemishes located at the back of a strand, so they are less visible.

  6. Nacre Quality: When luster is matched throughout a piece of pearl jewelry, that demonstrates consistent nacre quality, as nacre quality determines the luster.

No two pearls are exactly the same, which means that even beautifully matched pearls will feature variations in color, luster, shape, etc. It can take a very long time to find pearls for an entire strand that match. Highly trained graders may have to sort through thousands of pearls to create a single necklace.

This is the nuance of pearls. Every pearl is created by an animal. Every piece of pearl jewelry relies on a human seeing and highlighting the benefits and beauty of magical creation.

Tune in next week to look at some of my favorite pearl varieties!

Ocean of Pearl Strands

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