0.2 Carat Round (4.35×4.35×2.62mm)

Depth percentage of Round cut is the ratio of the total depth (measured from table to culet) to its average diameter. The total depth percentage of this diamond is 60.2%, which is OK.

Depth percentage for rounds is calculated with the following formula:

The face-up size of this 0.2 carat Round (4.35×4.35×2.62mm) is out of normal range for 0.2ct diamonds of this shape. Compared to 0.2 carat Round reference diamond, this diamond appears too big when viewed from the top. You might think that's a good thing, however, it's not. This is a so called spread cut.

A spread cut is a diamond that is cut to maximize spread instead of optimal light performance. From above it looks larger than an ideal 0.2ct diamond. This is not a good thing. Spread cuts are typically too shallow, which allows light to leak out of the stone resulting in less light being reflected back to the viewer's eye.

Spread cuts usually look lifeless and flat, and can sometimes exhibit a fish-eye effect. They may also come with an extremely thin girdle which can easily chip.

Face-up area is a measure of the size of the diamond when viewed from above. It tells you how big the diamond is at the girdle plane. It's important for a diamond to have sufficient face-up size for its carat weight.

Face-up area per carat is calculated by dividing face-up area of the diamond with its carat weight. It tells you how many square millimeters of the top surface area a diamond is showing or would show for 1 carat weight. This can be useful when comparing stones of similar weights as it tells you how much spread per carat you will get.

Top surface area = 14.86 mm²
Weight = 0.2ct

Face-up area per carat = 14.86 ÷ 0.2 = 74.3mm²/ct

Round Brilliants don't show color as much as other cuts, so you can go quite a few steps down on the color scale without noticing any difference. The choice of color also depends on a setting:

	Solitaire	Small side-stones	Substantial side-stones
White gold/Platinum	J+	I+	same as side-stones+
Yellow gold	K+	J+	same as side-stones+
		e.g. pave setting	e.g. three-stone setting

Round Brilliants are great at masking inclusions, so you can go relatively low on clarity scale without sacrificing the appearance, as long as the diamond is eye-clean. SI1 or SI2 clarity offers great value for money.

Note: You can always go lower in clarity, but it's going to get increasingly difficult to find an eye-clean Round below the minimum recommended SI2 grade.

For best value, go with the lowest clarity possible that is still eye-clean. If a diamond is eye-clean, it doesn't matter, if it's flawless or SI2. It will look the same, provided all other characteristics are the same.

Professional and unbiased assessment of diamond characteristics is stated on a diamond grading report, commonly referred to as a certificate. Certificate, while not 100% reliable, is essential in determining a diamond's value.

The standard for diamond grading is pretty much set by GIA - Gemological Institute of America. They are the most reputable and consistent lab in the industry. AGS (American Gemological Society) is not far behind.

If a diamond is not certified by GIA or AGS, you can be pretty much certain that you are looking at lesser quality than indicated. This puts you in a bad position of not knowing the true diamond characteristics, which almost always results in overpaying. That is why a certificate from a well-respected grading lab is so important.

Blue fluorescence can have a positive, negative, or zero effect on a diamond. Diamonds in the lower color range (H or lower) can benefit from it, as it can make them look whiter, more colorless. On the other hand, strong fluorescence can cause a stone (especially in the higher color range D-G) to appear hazy or milky under certain light conditions. One of the biggest benefits of fluorescent diamonds is that they generally cost less.

GIA grades fluorescence as None, Faint, Medium, Strong, and Very Strong.

Faint fluorescence will have zero effect on color and overall appearance. Fluorescence of this type is not an issue and shouldn't be a purchasing factor.

Medium fluorescence will in most cases have zero to very small influence on color and overall appearance, however, colorless diamonds can sometimes exhibit negative effects and should be examined in different light conditions before purchasing.

Strong/Very Strong fluorescence requires caution. Generally, it's not a good idea to buy a colorless diamond with Strong/Very Strong fluorescence. As for lower color diamonds, even they can sometimes look hazy with strong fluorescence, so never buy a stone with this type of fluorescence without careful visual inspection.

The problem with diamond grading labs other than GIA or AGS is that they are looser and more inconsistent in their grading standards. A GIA color H is an IGI color G and an EGL/HRD color F. The same goes for clarity.

While it's true that IGI, EGL, and HRD diamonds are sold at a discount, you can be certain that the same stones would cost less, if they would be certified by GIA or AGS. Why? Because they would get lower grades and thus lower price. Lower than discounted IGI, EGL, and HRD stones with higher grades.

Diamond merchants use IGI, EGL, HRD, and alike to maximize their profits. They know they can sell diamonds with inflated grades for more, even if they're sold at a substantial discounts. Some merchants also use their in-house certification, usually for the sole purpose of increasing their profits. These kinds of certificates are meaningless.

Buying shy means choosing a diamond that falls just under the full-carat or half-carat mark. So instead of 1ct stone you go for 0.95ct; instead of 1.5ct you go for 1.4ct, and so on.

Because diamond prices jump dramatically at full-carat and half-carat weights, you can save a considerable amount of money when buying shy. Going up to 10% down in weight will result in a slight difference in size, but so slight it'll barely be noticed, if at all. To check this for yourself, use this site to compare different sizes.