Birthstone buying guideGemstones are an investment in many ways. Precious gems are called 'precious' for a reason - they have intrinsic value. Some of the highest valued gems can easily cost thousands of dollars per carat - and those values seldom drop in the market. Even if you're not buying for investment purposes, though, you want to be sure you get the most value for your money. We're offering this guide to help you choose the best birthstone gem that you can afford. In the pages that follow, we'll explain the various factors that are considered in grading and pricing gems - what they are, why they're important and how to judge them. Keep in mind though, that jewelry, like clothing, is a matter of personal taste. In fact, in many cases the 'off' colors are absolutely stunning - and will cost far less than a gem with 'ideal' color. A smaller stone with only minor inclusions may be more beautiful - and cost less - than a larger gem with a single flaw. Grading is objective - the flaw that decreases the value of the stunning emerald you saw may be precisely the reason that it sparkles in a way that you can't resist. In the end, the most important factor in buying the perfect birthstone is how it makes you feel. Or, as my mother used to tell me when I asked her what she thought of my new dress, 'You're the one who's going to wear it. Do you like it?” Value factorsMost people are familiar with the four C's - carats, cut, color and clarity - of diamond buying. The same four C's apply to colored gemstones as well, though the grading is not nearly as uniform. Still, birthstone gems are graded and priced on those four qualities, as well as place of origin, possible treatments and current fashion. It's not unusual for a particular birthstone to suddenly rise in value because it is currently in vogue to wear it. There's no predicting fashion as a value factor, but the others are fairly stable. Here's an overview of what you should look for when buying a birthstone gem. Judging colorsWhy color matters Color is the single most obvious property of any gemstone, and in older times, was the way that gems were classified. It's still the most important factor in judging the value of a gemstone. From aquamarine to zircon, each stone has an 'ideal' color range, and stones that fall outside that range are usually less expensive. That doesn't mean that they're of lesser quality, or less beautiful by any means! It only means that they don't meet the standard color for 'ideal' for that particular stone. You may find the color to be perfect in your eyes. Darker is not always better. The darkness of the color in a gemstone is not the truest indicator of a gem's worth. In many cases, it's the midtone ranges of a color that define the 'ideal' color. A sapphire that is too dark won't reflect and refract the light properly, robbing the stone of the classic blue fire that makes the sapphire such a prized stone, and a color that is 'too light', as in the ice blue topaz mined in Brazil, will be overpowered by faceting and cutting. How to judge color Look at the gemstone under all different lighting conditions. The jeweler will often show the gem against a background that's meant to intensify its color and mask its flaws. If possible, try to view the gemstone against a white background for best judgment of its color quality. What about color-change gems? Color change gems have taken the market by storm over the past decade or so. These are stones that appear to be different colors when viewed from different angles or in different lights. The most well known of these is the alexandrite, which shows a marked difference in color when viewed from different angles, and the tanzanite, which seems to be two different colors under natural and incandescent light. The reason for the color change is double refraction when light is viewed through different directions in the gem's crystal structure. Most stones do it to some extent, but it's only viewable through a polariscope. True color-change gems can command high prices in the gem market for their chameleonic qualities. Among the gems that have color change varieties are chrisoberyl, alexandrite, sapphire, garnet, tourmaline, tanzanite and diamonds. The most valuable are those that have clear, definitive color changes under different conditions. For specifics about the ideal color for each of the birthstone gems, see the individual buying and care guides for each stone. Judging clarityAfter color, clarity is a major determining factor of a gemstone's value. In general, the most valuable stones are transparent with no obvious flaws or impurities (called inclusions) to mar the refraction of light. There's no specifics for grading colored gems for clarity as there is with diamonds, but for the most part, darker colored gems show inclusions less. Because of this, inclusions affect their value less. Inclusions are more obvious in paler stones, so affect the value more severely. The position and size of the inclusion also makes a difference in how much it affects the value of the stone. Unlike diamonds which are examined for clarity face down, colored gemstones are examined from the top. Because of that, if an inclusion or flaw doesn't show in the face up position, it won't affect the value much at all. Likewise, the setting that you choose for a gem may hide an inclusion, making it unimportant even if it did bring the price down for you. Finally, there are rare cases where inclusions actually enhance the value of a stone. The star in star sapphires and the cats eye in chrisoberyl are caused by inclusions. In some cases, the shape of the inclusions is characteristic of a particular mine or region, and creates a 'signature' of sorts that can increase the value of any stone that bears it. CaratsAll gems are weighed in carat weight. The origin of the carat is, believe it or not, the carob seed. In ancient times, those who sold gems weighed them by balancing the other side of a balance scale with carob seeds. One carob seed is equal to .2 grams, and this is so uniform that even today's sophisticated electronic scales have only found differences of less than three thousandths of a gram between individual carob seeds. In general practice, a .5 carat gem (or a 5 point gem) will cost less than a 1 carat gem - but there are other factors that come into play as well. A flawless half-carat gem could well cost more than a less perfect stone that weighs a full carat. There are a couple of other factors concerning weight that also make a difference in price. Popular weights cost more The price increase for size doesn't often run smoothly. There's often a big jump at the 1 carat size, for instance, with a single 1 carat stone costing considerably more than two .5 carat stones of the same quality. This is in part due to larger stones being more rare, and in part to the fact that people buy stones in round sizes. That means you'll pay less per carat for a 1.15 carat gemstone than you will for a 1.20 carat gemstone. If you have a choice, choose a stone in an 'off' size. Carat refers to weight, not size. Birthstones vary in density from one to another, so a 1 carat aquamarine may be smaller than a 1 carat emerald. Prices are set by weight, not size - but visual impact is a matter of size, not weight. If you want a larger gem for the same price, you may find it by looking at similar stones in the same color range. Judging cutWhy is cut important? Cut is the final major factor affecting the value of a gem. This is not to be confused with shape, though many cuts do have a characteristic shape. The cut is the overall effect of the faces and angles that are imparted in a gem to enhance its refractive properties. Light refraction angles Gems get their sparkle and fire from the way that light refracts from the angled surfaces. Much like a prism, light enters the top face of the stone, and bounces from one angled surface to another before aiming it back out the top of the stone. If a gem has been cut poorly, the light can 'leak' out the bottom of the stone, robbing it of its fire and beauty. The best way to judge the clarity of a gemstone is in natural light against a light colored background. Dark spots and patchy color are signs of poor cutting angles that don't refract the light properly. Recommended cuts for particular stones Some styles of cut were developed specifically to exploit or downplay properties of specific stones. The rectangular emerald cut, for instance, was developed especially for the emerald, which fractures easily when being cut. The long, even lines and minimal facets of the emerald cut show of the fire of the gem beautifully but lessen the danger of damaging the stone while cutting it. Laser cutting Laser cutting has given rise to increasing fancy and complex shapes in gem cutting. Flowers and hearts are among the most common of the 'sculpted' shapes available in semi-precious and precious gems. Keep in mind that the main purpose of the cut is to enhance the refractive quality of the gemstone. If it's poorly cut without proper faceting, you might as well buy plastic. Does your gemstone have a pedigree?For some gems, their place of origin can add to their value. Australian opals, for example, are among the most highly valued in the world. In most cases, there is no real way to tell if the gem actually originated from a particular mine or region except a certificate - and in most cases, it doesn't matter except to a true connoisseur or collector. If it's important to you that your birthstone is a Russian opal, then ask for a certificate of authenticity. Treatments for gemsMost colored gems are treated in some way to enhance their color or clarity these days. It's so much expected, that stating that a gem is completely natural, untreated, or unenhanced is a major selling point that can add to the value of the gem. In fact, there are particular treatments that are often not even mentioned because it's accepted and expected that they were used. Expected treatments for colored gems:
ConclusionIn general, keep in mind that color, clarity, carat weight and cut will affect the value of the gem that you choose - but don't let monetary value be your sole guide. Some of the most beautiful stones in the world are among the most affordable. Tiny flaws that reduce value, slightly off coloring and sizing that isn't quite standard can all bring the price of a stone down - without affecting its appearance in the least. If you find a great bargain on a beautiful stone, snap it up no matter what the experts tell you about its quality. After all, you're the one who'll be wearing it. |
