The '4C' represents the characteristics used to evaluate the quality and value of a diamond. These four characteristics all have an impact on each other to determine the price of a diamond. Here they are: Carat: This is probably the most well-known. Carat is a measurement of weight for diamonds and other precious stones. One carat is equivalent to 0.2 grams. Heavier, larger diamonds tend to be rarer and, consequently, more expensive. To give you an idea, here are the measurements in millimeters for different diamond shapes : Carats Round Oval Radiant/emerald Princess Pear 0.25 ct. 4 mm 5 x 3 mm 4.3 x 3 mm 3.25 mm 5 x 3 mm 0.50 ct. 5 mm 6 x 4 mm 6 x 4 mm 4.5 mm 6 x 4 mm 0.75 ct. 5.75 mm 7 x 5 mm 6.5 x 4.5 mm 5 mm 7 x 5 mm 1.00 ct 6.5 mm 7.7 x 5.7 mm 7 x 5 mm 5.5 mm 7.7 x 5.7 mm 1.25 ct. 6.8 mm 8 x 6 mm 7.3 x 5.5 mm 6 mm 8 x 6 mm 1.50 ct. 7.3 mm 8.5 x 6.5 mm 7.5 x 5.8 mm 6.5 mm 8.5 x 6.5 mm 1.75 ct. 7.75 mm 9 x 6.5 mm 8 x 6 mm 6.75 mm 9 x 6.5 mm 2.00 ct. 8 mm 9 x 7 mm 8.2 x 6.2 mm 7 mm 9 x 7 mm Color: is the absence of color in the diamond. The color of a diamond refers to the specific hue present in the precious stone. This characteristic plays a crucial role in determining the value of a diamond. In fact, the closer a diamond is to being colorless, the more valuable it is. The grading begins with the letter D, symbolizing the absence of color, and extends to the letter Z, which corresponds to a light yellow or brownish hue. Many color nuances are so subtle that they remain invisible to an untrained eye. However, these slight differences have a significant impact on the quality and price of a diamond. D-E-F: These diamonds are classified as 'colorless' because they have almost no hue. Their rarity and purity make them highly prized. G-H-I: These diamonds are described as 'almost colorless.' They may reveal a slight hue visible to expert eyes while retaining exceptionally appreciated quality for their beauty. J-K-L: Diamonds weighing less than 0.50 carats may appear almost colorless, but as they reach a larger size, the color becomes much more noticeable. The color will also stand out if the ring setting is in white gold. M-N-O: These diamonds exhibit a slight yellow or pale brown tint, which is noticeable to the naked eye, especially when the diamond is viewed in a well-lit environment. It's from the M grade onward that consumers typically begin to notice a difference in color. Z: These diamonds are situated at the lower end of the GIA color scale. They exhibit a distinctly pronounced yellow or pale brown hue, which is typically visible to the naked eye. You may wonder why the GIA color scale starts with the letter D instead of A. This decision was made by the GIA for historical and industry convention reasons. By choosing the letter D, the GIA established a neutral and objective foundation for evaluating diamond color. This approach also helped avoid any preconceptions associated with previous notations like "A" or "AA," which some sellers used to designate diamonds as higher quality based on color. Clarity: is the internal and external characteristics of a diamond. The clarity of a diamond refers to the unique birthmarks of a diamond, either internal, called inclusions, or external, called imperfections on the surface. Diamonds without these inclusions and imperfections are rare, and rarity affects a diamond's value. Every diamond is unique. None is absolutely perfect under a 10x magnifying loupe, although some come close. The GIA clarity scale contains 11 grades, starting with 'Flawless' (FL) for a diamond with no inclusions and going up to 'Inclusions visible to the naked eye' (I3). As you move down the clarity scale, the presence and visibility of imperfections increase, and the value of the diamond tends to decrease. The majority of diamonds fall into the VS (very slightly included) or SI (slightly included) category. VVS (very, very slightly included): Inclusions are challenging to see for an experienced evaluator under a 10x magnifying loupe. VS (very slightly included): Inclusions are minor and range from difficult to fairly easy to see for an experienced evaluator under a 10x magnifying loupe. SI (slightly included): Inclusions are visible to an experienced evaluator under a 10x magnifying loupe. I (included): Inclusions that are visible to the naked eye and may affect the diamond’s transparency and brilliance to varying degrees. Cut: The cut of a diamond refers to how it has been shaped and fashioned. A good cut allows the diamond to reflect light optimally, giving it its brilliance and sparkle. Cut assessments include factors such as depth, table size, facets, and symmetry. The Gemological Institute of America (GIA) cut grade scale is used to evaluate the quality of a diamond's cut, which includes factors like proportions, symmetry, and polish. The GIA cut grade scale ranges from Excellent to Poor, with each grade reflecting the overall quality of the diamond's cut. Excellent: Diamonds in this category have excellent proportions, symmetry, and polish. They are known for exceptional brightness, fire, and scintillation. Very Good: Diamonds with very good cut grades still offer high-quality light performance. They have slightly less precision in proportions, symmetry, and polish compared to Excellent cuts. Good: Diamonds with a good cut grade exhibit acceptable proportions, symmetry, and polish. They offer good light performance but may not be as brilliant as higher-grade cuts. Fair: Diamonds in this category have noticeable deviations from ideal proportions, symmetry, and polish. They may exhibit reduced sparkle and brilliance. Poor: Poorly cut diamonds have significant deviations from ideal standards, resulting in reduced light performance and overall visual appeal. The cut grade is an important factor in assessing a diamond's overall beauty and value. A well-cut diamond will maximize its ability to reflect and refract light, creating a stunning visual effect. The GIA cut grade helps consumers make informed decisions when choosing a diamond. In conclusion, the '4C' are the fundamental criteria used to evaluate the quality and value of a diamond. Each of these criteria - Carat, Color, Clarity, and Cut - interacts to determine the price and overall appearance of the diamond. The choice among these characteristics depends on personal preferences and the buyer's budget, but understanding the 4C is essential for making an informed decision when purchasing a diamond.