The cut grade is the most important facet of a diamond; an objective measure of its light performance, it is also what one would typically refer to as sparkle and brilliance. When a diamond is cut with the proper proportions, light is returned out of the top of the diamond (referred to as the table by gemologists.) If it is cut too shallow, light leaks out of the bottom. Too deep, and it escapes out of the side.
Ideal cut: Represents roughly the top 3% of diamond quality based on cut. Reflects nearly all light that enters the diamond. Exquisite and rare.
Very good cut: Represents roughly the top 15% of diamond quality based on cut. Reflects nearly as much light as the ideal cut, but for a lower price
Good cut: Represents roughly the top 25% of diamond quality based on cut. Reflects most light that enters. Much less expensive than a very good cut.
Fair cut: Represents roughly the top 35% of diamond quality based on cut. Still a quality diamond, but not as brilliant as a good cut.
Poor cut: Diamonds that are generally so deep and narrow or shallow and wide that they lose most of the light out the sides and bottom. Jewelers typically does not carry these.
A diamond's color grade is actually gauged by its lack of color - with the criteria being how prominent its shade of yellow is; the less color a diamond has, the higher its color grade. A diamond’s color is generally considered to be the second most important characteristic in the selection process after its cut, since the human eye generally notices a diamond's sparkle first and its color second.
Color Grade sheet
D: Absolutely Colorless - the highest grade available, with no detectable color whatsoever.
F-E: Colorless - any traces of color are typically only noticeable to expert gemologists.
H-G: Near colorless - colors are difficult to detect by the naked eye, unless juxtaposed with diamonds of a higher grade.
J-I: Detectable color - slightly discernible tone or shade.
M-K: Noticeable color - a distinctly yellow hue.
Z-N: Has color - an opulent yellow tone.
Clarity specifies the natural imperfections that occur in all but the finest diamonds. These imperfections are referred to by gemologists by a number of different technical terms - including blemishes and inclusions, among others. Of course, diamonds with the least amount of imperfections receive the highest clarity grades. Because these imperfections are usually microscopic, they don’t affect a diamond's natural beauty in any detectable way. In fact, a diamond’s clarity actually has the least impact on its appearance - and although much is made of it, it is the easiest of the Four C’s to understand(Consider including an image.)
FL, IF (Flawless, Internally Flawless): Free of all imperfections, perfect by every measure. Very rare.
VVS1, VVS2 (Very Very Slightly Included, 1 and 2): Imperfections are very difficult to see, even with magnification. Excellent quality.
VS1, VS2 (Very Slightly Included, 1 and 2): Imperfections are somewhat noticeable with magnification, but not at all to the naked eye.
SI1, SI2 (Slightly Included, 1 and 2): Imperfections are clearly evident with magnification and may be visible to the naked eye.
I1, I2,I3 (Included, 1, 2 and 3): Imperfections are visible both when magnified and observed normally.
As the name might suggest, this refers to the weight of diamond. Carat weights are determined out of a possible 100 points. For example, a one-carat diamond is comprised of 100 points, ½ a carat of 50 points and so on.
Carat weight alone often does not precisely articulate its size; It is recommended that observing carat weight alongside two other characteristics - the distance across the top of the diamond measured in millimeters and its cut grade - to achieve a better understanding of diamond sizing.
To begin with, the distance across the top of the diamond is an important facet of the process; viewing it from this angle may make it appear larger than it actually is, and it also serves as the vantage point from which we see a stone when setting it into a ring.
Furthermore, a diamond's cut grade is a significant gauge of carat weight; a diamond cut with adequate proportions will project the most amount of light (sparkle) out of its top. As such, when a diamond has an ideal cut, the light reflected on top gives it a larger appearance. Conversely, the majority of a poorly cut diamond’s weight may be hidden in its base, giving it a smaller appearance than what its carat weight might indicate.
Considering this, it is possible to have a diamond of a lower carat weight but a higher cut grade that appears larger than a diamond with a larger carat weight but is of a poor cut grade.
After selecting your cut, color, and clarity grade, it will be easy to find the carat weight of a diamond falling in your price range.
Choosing A Diamond Size
If you're working within a strict budget and a large carat weight is important to you, consider a diamond with a good cut - SI1-SI2 clarity - and an I or J color grade. Diamond prices jump at the full and half-carat weights, and diamonds just below this not only cost significantly less, but small size differences are also almost impossible to detect - since carat weight is distributed across the entirety of the diamond
Please keep in mind that the smaller the finger, the larger the diamond will appear: a 1.5-carat diamond solitaire looks much larger on a size 4 finger than a size 8. Not all settings will fit all diamond carats or shapes. If you have already selected a setting, check the diamond specifications of your ring.
What is a Certificate?
A diamond certificate - also called a diamond grading report or diamond quality document - is a report created by a team of gemologists after a diamond is evaluated, measured and scrutinized using trained eyes, a jeweler’s loupe, a microscope, and other industry tools. A completed certificate includes an analysis of the diamond’s dimensions, clarity, color, polish, symmetry and other characteristics. Moreover, many round diamonds will also include a cut grade on the report.