Diamond Education

The value of a diamond is determined by the 4C's - Color, Clarity, Cut and Carat. We have described each of these in detail below.


Most customers understand that color is an important factor in determining the value of a diamond. Also, when one starts talking about diamond color grades, they expect to be able to tell the differences in the color grades instantly. However, the differences in the colors are quite subtle at times and it requires a trained eye to notice one color grade difference in diamonds. The difference in color grades can be thought of as differences in the whiteness of paper. For example, the difference in whiteness of a facial tissue, a local newspaper, a sheet of computer paper, and a small index card is minor but the color difference does exist. Also, the color in diamonds can be either yellow (in most cases) or brown.

Diamond color grade ranges from D - Z, where D is the whitest (or colorless) and Z is light yellow or brown. The whiter or colorless a diamond is, the rarer it is and thus more valuable it is.

D-F, colors are viewed as colorless and are very rare, where G-I colors are near colorless and still rare. J-K colors have a very light color but are ideal for yellow gold mountings because diamonds in these mountings still look white because of the surrounding. Colors below K are not advised by GemsNY because they have traces of color which can be detected by an untrained eye. GemsNY carries diamonds in color grades from D-K color only. We don't carry colors below K to ensure you are selecting the highest quality diamonds.


Clarity is one of the major components in determining diamond value. Clarity in a diamond is determined by the number, type and size of the inclusions when viewed under 10x magnification. Diamonds which are very clean are very much sought after and are quite expensive and rare. Diamonds with VS2 clarity and above are considered "Eye clean". It is best to pair VS2+ clarity diamonds with D-F color diamonds. For diamonds that are SI clarity, for best value it is best to pair with G-I color.


The cut of a diamond is the main ingredient in determining how much brilliance and fire that diamond will have. There is a strict range of proportions that a diamond's cut has to meet in order for that diamond to exude maximum brilliance and fire it is capable of. Although different jewelers have different perceptions of what ideal proportions are, there are certain ranges which are accepted as ideal by all. Generally, in order for these ideal proportions to be met, there is a greater weight loss than if the diamond was to be cut to retain the maximum weight, therefore better cut diamonds cost more money.

There is no one particular measurement which dictates a diamond grading but rather it is a combination of factors that determine the cut grade. The main factors that are considered are depth percentage, table percentage, polish grade and symmetry grade and minor factors include pavilion angles, crown angles, girdle thickness etc.

Natural Diamonds Lab Created Diamonds

Carat Weight

Carat weight is the unit of measurement that is used by the jewelry industry to weigh all gemstones, including diamonds. One carat is equal to .2 grams or there are five carats in one gram. While the carat weight of a diamond is related to its size, the weight does not measure directly the size of a diamond. To gauge the size of a diamond (visual appearance) it is always better to look at the millimeter measurements as opposed to the carat weight.

hand image
Actual Diamond Size on Size 6 Hand
0.25 CT
2.0 CT


There are various gem laboratories out there providing their own independent judgments on diamond specifications. Unfortunately, often these laboratories vary in their strictness in grading of diamonds. Here we list only the most respected and well known laboratories:

GIA - Gemological Institute of America:

GIA Lab sets the standard for diamond grading and is by far the most commonly used and respected lab in the trade. The Diamond Dossier, is a GIA report issued for diamonds weighing less than 1 carat. GIA is the most prominent lab for natural white and color diamonds.

IGI - International Gemological Institute

An independent laboratory that uses state of the art high tech equipment to verify the quality of a diamond. This lab is the most prominent for lab created diamonds.

Diamond Care

Diamonds are very easy to take care of due to their hardness and durability. To keep your diamond jewelry sparkling you may want to clean it to remove the unwanted dirt and residue build up. Here are a few care tips to keeping your diamond jewelry clean and shiny.

  • (1) Avoid contact with make-up, harsh chemicals (i.e. chlorine and bleach), moisturizers and abrasives. It is best to take jewelry off when in contact with these items. Never swim or bathe with your jewelry on. It is also best to avoid hard impact activities such as exercising and gardening, which may scratch or chip the diamond.
  • (2) Clean your diamond by pouring lukewarm water in a bowl and mixing with mild cleaning detergent. Submerge your jewelry until the dirty and residue is moistened. Then use a soft toothbrush to clean the underside of the diamond. Once clean, rinse and dry with a soft cloth. For extremely dirty jewelry, you may need to repeat the process.
  • (3) Store your diamond jewelry individually and avoid contact with other jewelry to prevent scratching. For every day rings (such as engagement rings), we recommend a weekly rudimentary check to ensure that the center gem is not loose. Take off the ring and shake it next to the ear (can also tap) and see if you hear rattling. If you do, immediately stop wearing and get tightened.
  • (4) We highly recommend an annual maintenance of your diamond jewelry to have the gems tightened and jewelry cleaned professionally. This will ensure your jewelry lasts a lifetime.