About the 4C Standard

About the 4C Standard

What are the 4 C’s of diamonds?

Information is one of the most important tools you can have before you make a diamond purchase. The four Cs: color, cut, clarity, carat weight, can help you determine the exact diamond you're looking for.

Pair this information with a ball-park figure of what you want to spend and from there, you can feel secure about getting the best value for your money. Most of all, ask questions and don't be intimidated. Your jeweler wants you to be happy with what you choose, and you deserve to get exactly what you want!the most important characteristics to understand when making a diamond purchase whether for an engagement ring or just because.

Until the middle of the twentieth century, there was no agreed-upon standard by which diamonds could be judged. GIA created the first, and now globally accepted standard for describing diamonds - The 4C's. Today, this is the universal method for assessing the quality of any diamond, anywhere in the world.

The creation of the Diamond 4C's meant two very important things: diamond quality could be communicated in a universal language, and diamond customers could now know exactly what they were about to purchase.The four diamond characteristics are graded by professionals on a consistent scale, giving you a tool to evaluate diamonds. By reviewing the 4C’s of a particular diamond, you can better determine if the diamond is of high-quality. Tianyu gems is here to help guide you and teach you how to buy the best diamond for your money. In this Article, I will go through the 4C’s and what they all mean.  As always, if you have more questions, please feel free to contact me,I would be happy to assist you.


Many trade professionals consider Diamond Cut to be the most important of the 4Cs. Why? A small but well-cut diamond will sparkle, while a larger but poorly cut diamond will look flat. Cut does not refer to the shape of the diamond, but more about how well a diamond’s facets interact with light. Granted, because diamonds are faceted, they all will have some “sparkle”, but the better the cut, the more sparkle a diamond will have.The cut of a diamond is the factor that fuels a diamond’s fire, sparkle and brilliance. Precise workmanship is required to cut a diamond so its proportions, symmetry, and polish maximize its beauty. The allure of a particular diamond depends more on cut than anything else.

There are Four Types of Diamond Cut:Ideal, VeryGood, Good and Poor.

   ·   Ideal: Extreme Sparkle, Top Class Polish and Symmetry.


   ·   Very Good: Lots of Sparkle. Great Polish and Symmetry.


   ·   Good: A Little Amount of Sparkle. Just Enough Polish and Symmetry.


   ·   Poor:  Will Not Sparkle Enough. Unsatisfactory Polish and Symmetry.


 There are three important elements of cut:

   ·   Brightness:the light reflected in and out of the diamond. Having perfect proportions will prevent light leakage and thus, make the gem appear brighter.

   ·   Fire:White light breaking up into the colors of the rainbow.

   ·   Scintillation:Light and dark areas that move across the diamond when its position to a light source changes.


 Even if two diamonds are given the same grade on the diamond cut chart, cuts vary significantly among diamonds and diamond cutters. At times, a cutter may aim for maximum Carat weight, leaving the diamond too deep or too shallow for optimal light reflection. Other times a diamond may be cut to minimize the number of inclusions, improving its Clarity, but forgoing maximum sparkle. Even an Ideal cut diamond may have a yellow tint that is too noticeable and detracts from the gem’s beauty.

 More importantly, though, is ensuring Cut is a focal point of your diamond selection. Even a pristine 2 Carat Diamond with no blemishes or color tinting can be dull if it’s not cut exceptionally well. Cut is the biggest indicator of beauty, and should be made priority over the other C’s. As an example, this 1.50 Carat Round Brilliant is graded well for each“C”but lacks a vivacious sparkle.

 It’s essential to note that a top grade designation on the diamond cut chart, such as Excellent, doesn’t necessarily indicate an outstanding diamond cut. Almost 55% of all diamonds sold online are Excellent cuts. Some are stunning, while others are mediocre.  Altogether, a well-cut well-balanced diamond is going to determine whether or not it sparkles, displays flaws, exhibits color, and so on, so one needs to consider the overall quality of the cut when making the purchase.


  What is Diamond Clarity?  Clarity is the state of being clear or transparent. Diamond clarity is the presence or absence of characteristics called inclusions in the diamond.

The clarity of a diamond refers to how clear the diamond appears and is an assessment of small blemishes and inclusions. Evaluating diamond clarity involves determining the number, size, relief, nature, and position of these characteristics, as well as how these affect the overall appearance of the stone. While no diamond is perfectly pure, the closer it comes, the higher its value. The GIA has also produced a Clarity Scale to substantiate a universal standard for diamonds, that is scientifically determined using a GIA patented microscope. This scale consists of six different categories and has 11 specific grades.

· Flawless (FL)

No inclusions and no blemishes visible under 10x magnification

· Internally Flawless (IF)

 No inclusions visible under 10x magnification

· Very, Very Slightly Included (VVS1 and VVS2)

Inclusions so slight they are difficult for a skilled grader to see under 10x magnification

· Very Slightly Included (VS1 and VS2)

Inclusions are observed with effort under 10x magnification, but can be characterized as minor

· Slightly Included (SI1 and SI2)

 Inclusions are noticeable under 10x magnification

· Included (I1, I2, and I3)

Inclusions are obvious under 10x magnification which may affect transparency and brilliance


Many inclusions and blemishes are too tiny to be seen by anyone other than a trained diamond grader. To the naked eye, a VS1 and an SI2 diamond may look exactly the same, but these diamonds are quite different in terms of overall quality. This is why expert and accurate assessment of diamond clarity is extremely important.


Diamond Color Actually Means Lack of Color.

The diamond color evaluation of most gem-quality diamonds is based on the absence of color. A chemically pure and structurally perfect diamond has no hue, like a drop of pure water, and consequently, a higher value. GIA's D-to-Z diamond color-grading system measures the degree of colorlessness by comparing a stone under controlled lighting and precise viewing conditions to masterstones, which are stones of established color value.

 Many of these diamond color distinctions are so subtle that they are invisible to the untrained eye; however, these distinctions make a very big difference in diamond quality and price.


Around the early 1950s the GIA developed its colour-grading system, using letters to denote colour. This is achieved through a series of "master stones," where each stone is perceptibly different from the previous one. The GIA decided to name the top stone (the one showing no colour) "D" and then graded them down to "Z." The colour of a diamond is then determined by comparing it to the master stones.

The letter ’D’ was selected by the GIA as the highest colour grade as this was the failure grade in American school exams. At that time the top colour was referred to as either ’A’, ’A++’, ’A+++’, ’Super A’, or similar terms by the traders in the market. D was a colour that was never used, so the GIA used this as the top grade knowing that nobody else had used this letter.

The first group of diamond color grading scale is the colorless group: D, E and F. These diamonds are the most rare and the most valuable. To accentuate the lack of color in these diamonds, we recommend a platinum engagement ring.The next group is near colorless diamonds: G, H, I, and J. These diamonds will look colorless in mountings. (You may start to see a slight hint of yellow starting in I color diamonds, especially when set in white metals.) We think that this group offers the best combination of beauty and value: you have a colorless gem but you aren’t paying for the rarity of the colorless group that isn’t perceptible in normal everyday wear. We prefer G and H diamonds, which we think look colorless even in white metals. But if you are setting your diamond in a yellow gold setting or engagement ring, the slight yellow cast of an I or J diamond probably won’t be noticed.

The third group is diamonds with faint color: K, L, and M. We think these diamonds have an off-white color that you will notice in your engagement ring.


No. Naturally colored diamonds outside the normal color range are called fancy-color diamonds. The FTC provides no guidelines for the use of the term “fancy-color” in the US, but there is general agreement in the international trade that fancy-color diamonds are either yellow or brown diamonds that have more color than a Z masterstone or they exhibit a color other than yellow or brown.


Diamonds are sold by carat (which is written as ct.), the unit of weight, which is perceived by many in terms of size. The word "carat" derives its name from the carob seeds that people used in olden times to counterweight their balance scales. These seeds are so homogeneous in shape and weight that even today's sophisticated instruments cannot detect more than three one-thousandths of a difference between them. Currently one carat is equivalent to 0.2 grams or 0.007 ounces (of about the weight of a paper clip). One more way of expressing the weight is by means of points. One carat is equivalent to 100 points hence a 0.25 carat diamond can well be referred to as a 25 point diamond. The size of a diamond is relative to its carat weight.


Diamonds within each carat range have average millimeter sizes so you can approximate their visual size. Although each diamond is unique, these millimeter measurements are typically the norm, especially since diamonds today are cut with machines to ensure precision. To truly understand the diamond’s size, evaluate the measurements. Well cut Round diamonds have less depth than well cut fancy shaped diamonds (diamonds other than Round).


While Carat weight is an element to consider when buying a diamond, the overall appearance and brilliance should carry more importance. For example, a mediocre 1.5 Carat diamond will not shine as brightly—or draw as much attention—as a stunning 1.0 Carat diamond, no matter how much more it weighs. Rather than sticking to a certain number on the diamond carat weight chart, choose a diamond with an Excellent cut or Ideal cut in the shape you desire.

How the 4 C’s work together

Each of the 4 C’s contribute to the overall beauty of a diamond and make each stone unique. A Diamond, however, should be viewed as an organic whole. Because the eye has difficulty differentiating one diamond characteristic by itself, such as Clarity or Color, it is important to consider how the 4 C’s impact each other.

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