Diamonds
4Cs Diamond Color, Clarity, Cut and Carat Weight are collectively termed the 4Cs – the factors that, when combined, define a diamond’s quality and ultimately determine its value. GIA created the 4Cs of Diamond Quality, which has become the universal method for assessing the quality of any diamond, anywhere in the world. The creation of the 4Cs means that diamond quality can be communicated in a universal language so diamond purchasers know exactly what they are buying. Color GIA’s diamond color grading system measures the absence of color, starting with D as colorless and continuing to Z representing light yellow or brown. The distinctions between color grades are so subtle that they are often invisible to the untrained eye but can make a big difference in diamond quality and price.
Cut A diamond’s cut determines its sparkle. To fashion a stone with proportions, symmetry and polish worthy of an excellent cut grade requires artistry and workmanship. The finer the cut quality, the more sparkle the diamond has. Clarity Natural diamonds form from carbon exposed to tremendous heat and pressure deep in the earth. Diamonds often contain clarity characteristics, called inclusions or blemishes. Inclusions are enclosed within the gem and blemishes are on the surface of the diamond. If all else is equal, the closer a diamond is to flawless, with no inclusions or blemishes, the higher its value.
Carat Weight Diamond weight is measured in carats. One carat is equal to 0.2 gram, about as heavy as a paperclip. Since larger diamonds are more rare, they will cost more than a smaller gem with the same color, clarity and cut grades. Diamond Fluorescence Fluorescence is the visible light some diamonds emit when they are exposed to invisible ultraviolet (UV) rays. On a GIA diamond grading report, fluorescence refers to the strength, or intensity, of the diamond’s reaction to long- wave UV, which is an essential component of daylight. The light emitted lasts as long as the diamond is exposed to the ultraviolet source.
Diamond Treatments While treatments can improve a stone’s Color or Clarity, the presence of such enhancements may affect the diamond’s value – particularly if the price reflects its appearance after treatment. Buyers have a right to know whether a stone is natural, a diamond simulant or a diamond created in a lab, and whether or not the stone has been treated to enhance its appearance. Diamond Simulants While the appearance of diamond simulants is similar to that of natural diamonds, they are not diamonds. Common diamond simulants include glass and cubic zirconia (CZ), both of which are completely unrelated to diamond at the atomic level. Simulants are generally less expensive than the real thing. They allow consumers to enjoy the flash and dazzle of diamond-like jewelry and to inexpensively complement the latest fashion trend. But no matter how convincing the illusion, all diamond simulants have optical and physical characteristics that can be identified by a trained gemologist.
Laboratory-grown diamonds
A lab-grown diamond (sometimes called man-made or synthetic diamond) is the result of a technological process, as opposed to the geological process that creates natural diamonds. Lab-grown diamonds have essentially the same chemical composition, crystal structure, optical and physical properties of diamonds found in nature. Most lab-grown diamonds are categorized as either high-pressure, high-temperature (HPHT) or chemical vapor deposition (CVD) diamonds, depending on the method of their production. Since HPHT and CVD diamonds grown in a laboratory are virtually identical to natural diamonds, differences only become clear when they are analyzed in a gem laboratory.
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