Most agree that cut is the most important of the 4Cs, as it is the factor that determines a diamond’s sparkle, and has the biggest impact on a diamond’s appearance. There are three components to the cut of a diamond: brilliance (light reflected from a diamond), fire (dispersion of light), and scintillation (the sparkle when a diamond is moved). Diamonds are graded on GIA’s (Gemological Institute of America) Cut Scale from excellent to poor.
Each diamond is graded on GIA’s Color Scale of D (colorless) to Z (light yellow/brown), according to how noticeable its color is. Between D-F and G-J the color differences are most subtle and difficult for the untrained eye to differentiate. It is only through comparing diamonds in controlled lighting by a professional that the differences become evident. Even the slightest difference of color changes the value of a diamond.
Diamond clarity refers to the lack of natural blemishes and inclusions within a diamond. No diamond is completely perfect, though some come close to Flawless. Diamonds are graded on GIA’s Clarity Scale which ranges from Flawless to Included. A diamond’s clarity is the least visible of the 4Cs to the human eye, and does not visibly change a diamond’s beauty.
Carat refers to the weight of a diamond, but does not necessarily determine its size or quality. It is the combination of color, cut, clarity and carat that establishes a diamond’s value. The weight of the diamond is measured to the hundred thousandth of a carat, and is expressed in decimals, because even the slightest difference in weight will change the value of the diamond.
The value of gemstones is measured by its tone (depth of color), hue (purity of color), saturation (color’s intensity) and clarity (inclusions in the stone). Color is one of the most important factors with gemstones, and while inclusions on diamonds are undesired, inclusions on gemstones are to be expected, and sometimes even raise the stone’s value.
Emeralds have a hardness of 7.5-8 on the Mohs hardness scale, and are highly included. Though they are hard, emeralds are also brittle which make them hard to cut, set and clean. To improve their clarity, most are treated with oil.
Rubies have a hardness of 9.0 on the Mohs hardness scale, and their value is determined by the intensity of its red color. All natural rubies have inclusions, which are used by gemologists to distinguish natural from synthetic rubies
Sapphires are one of the strongest stones, second only to diamonds, and have a hardness of 9.0 on the Mohs hardness scale. Sapphires can be found in every color except red, as well as every shade of blue. Most sapphires today are heat treated to enhance the stone’s brilliant color. The more intense the color of the stone is, the higher the value of the stone.
Gold is measured in karats (k), which describes how pure the gold is. 18k gold is 75% gold, 14k gold is 58.3% gold, both of which are ideal for fine jewelry. About 50% of mined gold is used in jewelry, but gold is also used in electronics and medicine!
For more information on gold, please visit www.gold.org
To make it white, gold is mixed with alloys that are naturally white, and then plated with the hard element, rhodium. Over time, the rhodium plating can wear off, revealing the original metal color, and must be re-plated to restore the jewelry’s whiteness.
Gold is naturally yellow, and is mixed with alloys such as copper that makes it strong enough for everyday wear. Yellow gold jewelry does not need to be re-plated, and fewer people are allergic to the alloys it is mixed with. While strong, yellow gold is also malleable.
Platinum is the most durable of all metals. It is denser than gold, naturally white, and more pure than gold (95%), so it is more resistant to wear. Because it is so pure, platinum is also hypoallergenic. While all metals become scratched, platinum is unique in that when it is scratched, the metal becomes displaced instead of flaking off. Over time, platinum creates a layer called patina. Platinum is 30 times more rare than gold