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Saturday, June 2, 2007

Diamond Learning Guide

Cut
Illustration of diamond cut


The cut of a diamond determines how it reflects light, which is responsible for its sparkle or brilliance. A well-cut diamond is cut by a skilled professional to the best proportions possible so that light will be reflected from each of its mirrorlike facets and disperse through its top. Too shallow a cut will let light escape through a diamond's bottom, causing it to appear dull, while too deep a cut will allow light to be lost through a diamond's sides, making it appear dark.

Because a diamond with perfect color and clarity could nevertheless have poor brilliance if it is not well cut, many gemologists consider this to be the most important property to note when choosing a diamond. Diamonds can carry cut grades of Excellent, Ideal, Very Good, Good, or Fair.

Clarity
Illustration of clarity


No two diamonds are alike. A diamond's most distinguishing characteristics are its inclusions, marks that are often invisible to the naked eye. However, under a jeweler's magnifying loupe or microscope they can look like crystals, tiny rivers, or clouds. A diamond's clarity is determined by the presence or absence of inclusions--fewer inclusions mean better clarity--and how visible they are. The greater a diamond's clarity, the greater its brilliance and value. A diamond categorized as internally flawless will have no inclusions, but this is extremely rare.

Diamonds with very, very small inclusions are graded as VVS1 or VVS2. Those with larger inclusions are considered lower-grade. Diamonds with inclusions that are visible with the naked eye are graded I1 to I2.

Color

Though diamonds come in a wide range of colors, colorless diamonds have traditionally been considered the most valuable. Most diamonds are graded on a scale using the letters of the alphabet, from D (colorless), the best grade, through Z (a light yellow). It is difficult for the untrained eye to notice such variations in color unless stones are being compared side by side. The comparatively rare colored diamonds are known as fancy-colored and are also quite valuable. They range in hue from the more common yellow (also graded Z+ on the alphabetic scale) to pink, blue, green, red, and even black and white.

Illustration of color

Diamonds that are graded D, E, and F tend to be the most expensive because of their rarity. However, any diamond you buy should have a good balance of cut, color, and clarity, so as to impart the most brilliance and dazzle possible.

Carat
Illustration of carat weight


A diamond's weight is measured in carats, with one carat being equivalent to 100 points. You will often see a diamond referred to as a 3/4-carat stone or a 75-point diamond. Larger stones are often more highly valued, but size should not be the only consideration--high brilliance, which varies according to clarity, cut, and color grade, is highly desirable in a diamond.

Shape
Illustration of diamond shapes


The traditional round cut provides a combination of the best qualities a diamond can have. However, there are other shapes that can emphasize a diamond's different features. The choice of a shape is best based on personal taste and the design of the jewelry.

Care

Diamonds, as the hardest substance on earth, are resistant to damage. However, diamond jewelry is set in different metals, and care will vary from piece to piece. The girdle can be chipped by a hard blow, making a protective setting extremely important. Diamonds should be cleaned in a solution of one part ammonia to six parts water, using a gentle scrubbing brush to remove any dirt. It is a good idea to have them cleaned once a year by a professional jeweler, at which time the security of the setting can be checked as well. Diamond jewelry should be stored in a soft cloth pouch to ensure that the stone will not scratch other jewelry.
Certification

A diamond certificate represents independent verification that the stone purchased has all the qualities of cut, color, clarity, shape, and weight expected. It is a further indication of the condition and value of that diamond as represented on our site. Such certificates are issued by several agencies employing highly trained gemologists and provide an unbiased and accurate evaluation of the diamond. These gemologists scrutinize each stone to analyze its dimensions, clarity, cut, color, finish, symmetry, and other details.

Diamonds purchased from the Collection may be certified by the American Gem Society Laboratories (www.agslab.com), the Gemological Institute of America (www.gia.org), or the International Gemological Institute (www.igiworldwide.com). The type of certificate provided will be noted in the product specifications of your jewelry purchase; if you do not see a certificate type noted, one will not be provided.