Diamond Education – 4Cs

Natural Diamonds

Choosing a diamond should be fun and there's 4 things you need to know:

Along with all the excitement that comes from just getting engaged, also comes the revelation of what the ring looks like. For most, the center stone is what will catch the eye. The diamond on her finger should uniquely express how pure and everlasting the love between you truly is. So when shopping for that special ring, for that special someone, it is important you know what to look for to make the right decision.


The cut of a diamond does not refer to its shape but refers to the stone’s correct proportioning of its angles and facets, which greatly determine it’s brilliance, liveliness, and fire. It's all about how a diamond’s facets interact with light!


TThe less color, the higher the grade! Even the slightest hint can make a dramatic difference in value.


Clarity grades assess the number, size, relief, and position of inclusions and blemishes. There are white AND black inclusions, who knew?


Carat weight refers to the actual physical weight of a diamond; for diamonds that are one carat or less, most jewelers refer to carat weight in terms of points out of 100. Rarity means larger diamonds of the same quality are worth more per carat!


The cut of a diamond is believed to be one of the most important characteristics of a diamond. The manner in which the diamond is cut is in reality what will determine its brilliance. A good cut will be one that reflects most of the light that enters the diamond making it shine and sparkle more than a poor cut diamond, in which the light escapes and does not reflect as much.

The quality of the cut of a diamond depends on several aspects of the cut: Brightness, Fire, Scintillation, Weight, Ratio, Durability, Polish, and Symmetry. The cut is not to be mistaken for the shape; it is determined by mathematical equations, which have been performed for centuries. Diamonds need to be polished and cut with precise proportions in order to make it a good cut. The more precise, the larger and more brilliant the diamond will appear.

Overall, we can say that it is the cut of the stone that has the most affect on its appearance and determines its true beauty.


When it comes to color in a diamond, the less color you see, the better. A diamond that is mostly colorless will have a greater value than one who has more of a warm hue. Although most diamonds are not completely white, it is best to try to get as close as possible to a stone that lacks the most color in order to get the most value.

Color is determined by the chemical composition of the molten mass that makes the diamond. For example a diamond may have a yellow color because there was nitrogen incorporated in the chemistry. The intensity of the color is directly proportionate to the amount of trace elements present. If there is less trace of the element present, then the less color the diamond will have.

The color of diamonds is classified by grading scales. A color grade of D is the highest, or the most transparent, while a grade of Z is the lowest, or the one with most color.


Clarity refers to inclusions or imperfections found internally in a diamond. These imperfections can be anything from small cracks inside the diamond to even pieces of crystals from other materials. From all of the characteristics, clarity is the one that has the least impact on the physical appearance of the diamond because most of these imperfections are not visible to the naked eye.

It measures the degree of surface and internal inclusions that can appear white, black, colorless, red or green. Factors that may affect the clarity of a diamond are the size, color, visibility and number of inclusions. A diamond with few or no inclusions will be a more valuable diamond and have a higher clarity grade.


Although many people believe that carat solely refers to the size of a diamond, what it actually measures is the mass or the weight of the diamond. If you want to measure to the size of a diamond, you will have to take into account the carat weight, distance across the top of the diamond and the cut.

The measurement of the carat weight is frequently expressed in points. For example, One carat is 100 points, a quarter carat is 25 points, and so forth. This is similar to a Karat, (with the letter K) which is the unit measure of gold.

You should also keep in mind the difference in the labels of carat. For example, Ct is the symbol for the weight of a single diamond. However, CTW is the total carat weight of the entire piece, which may include multiple diamonds.

The Formula

What should you look for in each of the C’s?

“The one thing you should not trade off on is the quality of the cut,” said Shor. “Even a nice color stone, if not well-cut, will be dull and lifeless. But if it’s a middle color — like K — and it’s got a real excellent cut, it will pop and flash with all the sparkle that diamonds are famous for.”

After choosing the cut, “balance the color, clarity and carat weight based on your personal preference to find the best diamond for you and your budget,” said Amanda Gizzi, spokeswoman for Jewelers of America.

For example, for $3,000, you might pick a 1-carat, K-color stone with some visable inclusions, or a half-carat, G-color, with a very slight inclusion. An L or M-colored diamond at that price “will get you a 2-carat honker, but you’ll definitely notice the yellow and you’ll see some inclusions,” said Shor.

It’s easy to compare options online. At BlueNile.com, set your price range, then play with carat size and the other C’s to see tradeoffs.

Many websites list the 4 C’s of Diamonds for every ring they sell. Brick-and-mortar stores should be able to provide grading reports, whether from GIA or another expert lab.

Shape and Style

Engagement rings traditionally feature gold bands with a center diamond, though some have smaller diamonds on either side. Melissa Colgan, senior style editor for Martha Stewart Weddings, says the engagement ring that Prince William gave to Kate Middleton, a large sapphire surrounded by diamonds, has increased interest in rings with other gemstones.

Diamonds can be cut into many shapes. Round, the most common, offers “the biggest bang for your buck because the difference between the raw and cut diamond is smaller,” Colgan said. But she said unusual shapes with retro looks and names like marquise, Asscher and Pear are having a resurgence, partly because celebrities are wearing them.

Ethically Sourced Diamonds

We at Robinson Jewelers, along with the global diamond industry, have a zero-tolerance policy toward conflict diamonds. Through measures such as the Kimberley Process, which tracks diamonds from mine to market, the industry in partnership with the United Nations, governments, and non-governmental organizations, polices diamond exports to prevent the trade of illegal diamonds. At Robinson Jewelers, we only purchase diamonds through the largest and most respected suppliers who, like us, proudly adhere to and enforce the standards established by the Kimberley Process. All diamonds at Robinson Jewelers are warranted to be conflict free. Diamonds are mined throughout the world, including major mines in Australia, Africa, Russia and Canada.

Why We Love This Gemstone

Diamonds forms under high temperature and pressure conditions that exist only about 100 miles beneath the earth’s surface. A diamond’s carbon atoms are bonded in essentially the same way in all directions. Another mineral, graphite, also contains only carbon, but its formation process and crystal structure are very different. Graphite is so soft that you can write with it, while diamond is so hard that you can only scratch it with another diamond. In addition, two diamonds that appear to have everything the same on their grading reports, can have a drastically differnt price and a drastically different appearance even though they're the same on paper, these stones really do have their own personality and each one is unique!


The 4Cs, created by GIA, are considered the global language of diamond quality.


The diamond is the only gem composed of one single element: carbon.


Most diamonds formed more than a billion years ago, deep in the earth’s mantle.