What is clarity, and how does it affect how a diamond appears? A diamond's clarity is a qualitative measurement, i.e. descriptive versus measured in numbers, that takes into consideration the number and size of tiny imperfections present. Fewer inclusions and blemishes in a diamond puts it into a better clarity class. What people notice first about a diamond are its clarity and color. However, the imperfections contributing to a diamond's clarity are usually not visible unless the stone is viewed under a microscope. So, even though clarity is one of the big 4 C's of diamond value - clarity, color, cut and carat weight — imperfections aren't typically discernible.
Why is color important? Diamond color is another characteristic contributing to its value. Simply put, the more closely a diamond is to being colorless, the more valuable it is. This doesn't include the very rare natural hues like pink or blue, which are incredibly precious. The Gemological Institute of America (GIA) formed the color grading scale currently accepted as the industry standard. The scale starts with the letter "D," representing colorless, and graduates through the alphabet up to "Z," which characterizes diamonds that are light yellow or brown. A diamond receives its color grade by comparing it to stones of known color under controlled lighting and precisely defined conditions of viewing.
What is an eye-clean diamond? An eye clean diamond refers to a diamond that, to the naked eye, appears colorless and flawless. This is not to say that it doesn't have imperfections - they're just not noticeable without at least 10X magnification. According to the GIA and the American Gem Society, diamonds rated as flawless (FL); internally flawless (IF); very, very slightly included (VVS1 and VVS2); and very slightly included (VS1 and VS2) are deemed to be eye clean. These diamonds usually have a clarity grade of "SI3" or better and color grade of “I” or better. Purchasing eye-clean diamonds allows you to enjoy a larger diamond on a smaller budget.
What size diamond should I buy? Budget is always a top concern when deciding the size of diamond to buy. The price difference between a .5 carat ($720) diamond and a one carat ($3240) diamond is drastic. However, consider that a .5 carat diamond measures about 5.15 mm in diameter, while a one carat diamond measures about 6.35 mm in diameter. In the end, you’re paying a large premium for the extra millimeter.
How is cut measured? The cut of a diamond is measured using a device that is able to create a 3-D model of the gem, and calculate specific proportions and angles. Computer modeling allows one to see how light behaves when entering and exiting the top (upper surface) of a diamond.
What does diamond fluorescence mean? Fluorescent diamonds show a visible reaction when exposed to UV radiation. There is usually no difference in appearance between fluorescent diamonds and regular diamonds. About 30% of diamonds exhibit fluorescence, and unless the degree of fluorescence diminishes its visual clarity, it has little effect on the gem’s value.