Because pearls are known for their inner glow, a trait that sets them apart from other gems, this value factor trumps all others. According to GIA, “Luster is the most important of all the value factors to the beauty of a pearl.”
Dependent on many factors, among them nacre thickness and growth conditions, luster is only good when nacre is translucent and its plates overlap in such a way that the pearl appears lit from within. Thick nacre does not guarantee sharp luster, but it certainly helps. The sharper the reflection on a pearl, the better the luster. GIA defines four categories of luster:
• Excellent: Reflections are bright, sharp and distinct
• Good: Reflections are bright but not sharp, and slightly hazy around the edges
• Fair: Reflections are weak, hazy and blurred
• Poor: Reflections are dim and diluted
Luster is one of the easiest pearl value factors to rate. Just hold an object, like a pen, close to the pearl. (Be careful not to get ink on the gem.) The sharper the reflection, the better the luster, and the more valuable the pearl will be. Note, though, that each pearl type has its own characteristic luster. Akoyas are known for their sharp, fine luster, while South Sea cultured pearls, for example, have a subtler, softer glow.
Pearls are organic, and therefore “imperfect,” meaning they are not uniform, shiny, perfectly round orbs every time they come out of an oyster. Rather, as natural, layered objects, they show many surface characteristics such as abrasions, bumps, chips, cracks, pits, scratches and wrinkles. Most people will never see a perfect pearl in their lifetime, and indeed, minor surface irregularities do not detract from a pearl’s value.
As defined by GIA, there are four classifications of pearl surface characteristics:
• Clean: Pearl can be blemish-free, or spotless, or contain minute surface characteristics that are very difficult to see when examined by a trained observer
• Lightly blemished: Pearls show minor surface irregularities when inspected by a trained observer
• Moderately blemished: Pearls show noticeable surface characteristics
• Heavily blemished: Pearls show obvious surface irregularities, which can compromise durability
The pearl’s overall appearance will determine its value. Obvious or multiple surface characteristics or large blemishes that affect the gem’s durability will detract from its value, while a more clean-looking pearl is worth more. Most of us cannot afford a perfect strand of pearls, but, luckily, small bumps and blemishes can often be hidden by a drill hole. According to GIA, “…a completely clean pearl is a rare treasure. Since rarity influences value, the prices of such pearls run extremely high. Most consumers must settle for some degree of surface irregularity in the pearl they purchase. Even the finest pearls can contain minor surface characteristics.”
Directly tied to luster, nacre quality/thickness is a very important value factor which, fortunately, can be judged by the naked eye. It’s better, of course, to evaluate thickness with an x-ray machine or by cutting the pearl, but most of us don’t have such a machine, nor do we want to wear pearls that have been chopped in half. (Picture that for a minute!)
Take a look at the pearl you wish to evaluate. A chalky, dull appearance means that the nacre is probably thin. In some cases, the nacre is so thin that the bead nucleus shows through. Do not purchase these pearls—they won’t last!
GIA classifies nacre into three categories:
• Acceptable: The pearl’s nucleus is not noticeable and the gem displays no chalky appearance
• Nucleus Visible: The pearl shows evidence of its bead nucleus through the nacre. The pearl shows strong “blinking” (a flickering of light and dark) when it is rotated across a light source
• Chalky Appearance: The pearl has a dull, matte appearance
Thin nacre has a negative effect on a pearl’s value, although thick nacre does not guarantee sharp luster. Thin nacre can crack, peel or otherwise deteriorate and the pearls won’t last very long. (Unlike other gems, polishing a pearl does not restore its original beauty.) Pearls with thicker nacre are more durable and more valuable. Ask about nacre thickness if you have the opportunity.
Interesting fact: Many freshwater cultured pearls are cultured with mantle tissue only, rather than a mother-of-pearl bead, and, as a result, are nearly solid nacre. Many pearl experts say that today’s freshwater cultured pearls from China now rival the beauty of Japanese akoyas!
As you can imagine, this pearl value factor only comes into play when a piece of jewelry contains more than one pearl. Some designers intentionally mismatch pearls for aesthetic effect, but when a strand is meant to be uniform, how well the gems match is an important consideration. Fortunately, this is easy to determine. Just look at the strand and note any obvious differences in the gems. (Some jewelers will try to hide small or imperfect pearls near the clasp, so check this area carefully.)
When evaluating a matched strand, keep in mind that cultured pearls are organic, not poured from a factory mold. No two are exactly alike, therefore it is impossible to make a perfect match. This does not detract from the jewelry, though, as long as, on a whole, the piece is uniform. To test, look at the strand, hold it up close and also view it at arms’ length. Are the pearls the same overall size? Color? Shape? Luster? Nacre quality? If they look the same, they’re well-matched.
GIA defines three categories of matching:
• Excellent: Pearls are uniform in appearance and drilled in the center
• Good: Piece shows minor variations in uniformity
• Fair: Pearls are noticeably different from one another
According to GIA, “It takes an enormous amount of skill and labor to sort harvested pearls. The time and effort involved in producing a well-matched strand of pearls will reflect its market price.”
Because they are produced in different animals in different environments under unique conditions, each pearl type has its own expected characteristics. When the traits shown for a certain pearl are outside the norm for its type, the pearl will be more valuable.
Each pearl is unique, and uniquely beautiful. Which pearl and pearl type is the most beautiful? It’s up to you. (This author is partial to white baroque freshwater pearls and golden round South Sea pearls.)
Congratulations! Now you know what to look for and what questions to ask when shopping for pearls. Remember, a pearl’s worth depends on its overall look–how well it combines the seven value factors. Keep in mind that not all value factors are important to all people. You may be more interested in pearl color than pearl size, for example. As with anything, individual tastes reign supreme. Now, go forth and buy with confidence.