CARAT The weight of a diamond is generally given in carats. One carat equals 0.2 grams. The weight of small diamonds is frequently expressed in points, with one point equaling 0.01 carats. As diamonds increase in weight, their size becomes less predictable. Diamonds with a shallow cut can have a greater diameter than a deep cut with the same weight. So if size is important to you, focus on diamond measurements as opposed to carat weight. Diamonds that look big for their weight may have reduced brilliance and fire. An increase in carat weight does not produce the same increase in millimeter diameter. For example, there is a 25% increase in carat weight from 1.00 carats to 1.25 carats but less than 8% increase in diameter (6.5 to 7.0 mm). Look for diamonds that have a diameter measurement that is at least as large as the average for that carat weight. There is no need to pay for the carat weight you can't see.

CUT Cut refers to the proportions and shape of the finished diamond, and is the most important factor in determining the brilliance of a diamond. A classic round brilliant cut diamond has 58 facets - 33 on the top, 24 on the bottom and the culet ( 1 point at the bottom - another tiny facet ). The finished diamond should be symmetrical. The table should be symmetrical, well-centered, and flat, not sloping. The cutlet should be centered when viewed from the top. The crown and pavilion facets should be in exact geometric relation to one another. And, the girdle should be perfectly round exhibiting a straight edge when viewed from the side. Too Shallow Diamonds that are cut too thin or shallow allow the light to pass through the sides of the diamond and appear lifeless, dull, or flat in the center. Too Deep Diamonds that are cut too deep or high do not reflect enough light back through the top of the diamond and appear to be dark in the center.

COLOR The color scale is used to evaluate a diamond's internal tint, as well as playing a significant role in determining its price, colorless diamonds being the most desirable of course. Color is best evaluated in natural light, as high intensity artificial lighting can make the diamond appear to be of a better color grade than it actually is. Diamonds should also be examined for fluorescence, as blue photoluminescence will also make the diamond appear to be of a better color grade.     GIA Color grades: D-F    Colorless - tint nearly undetectable to unaided, trained eye even when compared to white standard. G-H    Near Colorless - tint almost undetectable to the trained eye, but apparent when compared to white standard. I-J      Near Colorless - trace of tint just detectable to the trained eye, but noticeably apparent when compared to white standard, K-M   Faint Yellow to Faint Brown - tint apparent to the trained eye and readily apparent when compared to white standard. N-R    Very Light Yellow to Very Light Brown - tint is easily apparent to the unaided, trained eye. S-Z     Light Yellow to Light Brown - tint is obvious to the unaided, trained eye.

CLARITY Clarity measures the relative visibility of external blemishes or internal imperfections (inclusions) naturally occurring within a diamond as evaluated by a qualified gemologist. The clarity scale (GIA) is divided into six primary categories: (F or FL) Flawless - no discernible surface blemishes or inclusions visible when viewed at 10x magnification. (IF) Nearly Flawless- insignificant surface blemishes and no internal defects visible at 10x magnification. (VVS-1 & VVS-2) Very, Very Slight Inclusions - extremely difficult to very difficult to find surface blemishes or minute inclusions at 10x magnification, but can be more readily seen at 10x once located at 20x magnification. (VS-1 & VS-2) Very Slight Inclusions - difficult to somewhat easy to find surface blemishes or minor inclusions at 10x magnification. (SI-1 & SI-2) Slight Inclusions - easy to very easy to find surface blemishes or readily noticeable inclusions at 10x magnification, but will usually appear to be "eye clean" without magnification, though some stones will show slight inclusions when viewed from the side against a white background (note: GIA does not recognize an SI-3 clarity grade). (I-1) Imperfect - surface blemishes or obvious inclusions are somewhat difficult to find with the naked eye, but are easy to see especially after being located with 10x. (I-2, I-3) Imperfect - surface blemishes or obvious inclusions are somewhat easy, or very easy to find with the naked eye.  I-2 inclusions will have an effect on either the diamond's aesthetic appearance (beauty) or durability (potential for cracking), I-3 inclusions will have an effect on both. Diamond prices increase dramatically as clarity category lines are crossed.  SI clarity is generally considered to be the best compromise between cost and appearance, providing excellent value for stones of G-I color and proper proportions (cut).  Buyers should exercise caution when making purchases from jewelry merchants who don't know or won't state the clarity of the diamonds offered.  Buyers should also be aware that due to the use of smaller diamonds in jewelry pieces, these diamonds are less tightly graded and broader clarity range (two grades, such as SI-1 to SI-2, or I-1 to I-2) specifications are therefore not uncommon.

SHAPES Deciding on a shape is a very important step in the selection process of your diamond. Following are some examples of the classic shapes of diamonds: Round Princess Oval Emerald Pear Heart Marquise Trillion Baguette