How to Choose the Perfect Diamond
Buying a diamond is one of the most important decisions a couple will make. Choosing the size and shape along with the style of the mounting are important personal choices. Understanding the characteristics that influence the brilliance, beauty and value of diamonds can make your buying experience more enjoyable and more fulfilling. Diamonds are like people—no two are ever exactly alike. Very subtle differences in the internal and external characteristics of each stone, along with subtle variations in color and cutting proportions, have a measurable effect on the value of two diamonds which may appear to be similar. Start with a good jeweler, one who’ll take the time to help you through the 4 Cs—cut, color, clarity and carat weight. Understanding the language of diamonds will put you more at ease in making your selection. The next step should be obtaining a diamond certificate from a reputable independent gemological laboratory. The certificate identifies and evaluates specific characteristics that determine the value of the stone you select.
THE 4 Cs
Cut
Cut actually means two things: the shape of the diamond (round, marquise, pear, oval, heart, emerald, princess, radiant, etc.) and the proportions of the stone. When a stone is cut to good proportions, light is reflected from facet to facet, then dispersed through the top. The better the cut, the greater the sparkle, brilliance and fire of the stone.
Color
Most diamonds look colorless. But there are subtle shade differences that range from colorless to yellow/brown. Diamonds are graded on a color scale that ranges from D (colorless) to Z (yellow/brown). Diamonds with no hint of color at all are extremely rare and are therefore, most valuable. Most gem quality stones appear to be colorless, but they usually have at least a hint of color.
Clarity
Almost all diamonds contain a combination of internal and external characteristics called inclusions and blemishes. Normally, they are too minute to be visible without powerful magnification. Some are even so small they require great skill and time to locate. The number, type, location, visibility and color of inclusions determines a diamond’s clarity and may influence its value.
Carat Weight
Like all precious stones, the weight or size of a diamond is measured in carats. A one carat stone is equal in weight to one hundred smaller units called “points.” Therefore, a fifty-point diamond, for example, is the same as a half carat. Carat weight is the most obvious factor in determining a diamond’s value, depending on the quality of its cut, clarity and color.
Grading Colored Stones
Gemstones are the most fascinating natural objects on earth. Ancient historical records show that primitive peoples adorned themselves with gems and believed that gems had magical powers. Some societies even used powered gems for medicinal purposes! The classification of gems in ancient times was mainly associated with color. In other words, all red stones were once called "ruby," all green stones were called "emerald," and all blue stones were called "sapphire." Today people wear gems for many different reasons, including fashion, sentiment, and prestige. As gems became associated with money, the need for accurate identification grew.
The introduction of manmade gems and imitation materials in the 1800's created an urgent need for experts who could separate the genuine from the fake. The invention of the first cultured pearls and green-glass emerald imitations in the early 1900's further created need for gemological expertise. Today virtually all gemstones, including diamonds, have a number of manmade counterparts and imitations.
The 4 C's of Colored Gemstones
Colored stones are graded in a similar way to diamonds. Color, clarity, cut, and carat weight are the main value factors. The difference is that these factors are evaluated and weighted somewhat differently than in diamonds. Diamonds are assigned very precise grades for color, clarity, and cut. In colored stones, color is the main consideration. Unlike with diamonds, a minor clarity difference rarely affects the price of colored stones.
Color:
Color in gemstones normally results from the presence of small amounts of trace elements. Some of these coloring agents are an essential part of the gem's composition, while some are introduced as an extra element when the gem is forming in the earth. Regardless, these elements are responsible for the amazing variety of colors we see in the many different gemstones. Even diamonds appear in virtually all colors of the rainbow. Generally, the more pure and intense the color, the more desirable and more valuable the stone will be. Once again, a top color is more important than a top clarity.
Clarity:
The internal purity or clarity of a colored stone is secondary to the color quality. Clarity characteristics are often a beautiful part of a colored stone--and a key to identification. Collectors even value some colored stones for unusual inclusion scenery. In fact, inclusions can actually increase the desirability and value of certain colored stones. They do this by creating what is called "phenomena." An example of highly valued and beautiful phenomena in colored stones is the star appearance in sapphires and rubies, which results from the presence of intersecting "needles" of the mineral rutile. The cat's eye phenomena in tiger-eye quartz is the result of a similar condition, except the inclusions are lined up in a parallel manner. The value of certain colored stones, however, can be diminished by the presence of inclusions, when those inclusions are so numerous that they interfere with the passage of light through the stone and make it look cloudy.
Cut and shape:
Colored stones are cut into a wider variety of shapes and proportions than diamonds are. Where the round brilliant-cut is most popular for diamonds, other shapes are better suited to show off a colored stone's beauty, such as oval, cushion, pear, marquise, emerald cut, cabochon, mixed-cut, trapezoid, and tablet. Each cut is chosen to show off the best color and preserve the most weight from a colored stone. Colored stone proportions also differ radically from those of a well-cut diamond. The bulk of a colored stone may be on the bottom where it has the best chance of returning the most brilliance and best color to the viewer. Certain colored gems look better in some cuts than in other. For instance, the majority of fine quality emeralds are cut in the traditional emerald cut shape. Opals are always cut with a smooth curved top (en cabochon). Fine quality rubies and sapphires are normally cut in oval or cushion shapes.
Carat weight:
The weight of diamonds and colored stones is expressed in carats. One carat consists of 100 "points" and is equal to 0.200 grams.
