Diamond jewelry, as some would put it, is the royalty among all gems. As such, assessing the value and quality of this gemstone had been refined to almost an exact science and a very fine art for hundreds of years now.
Today, dealing in diamonds either as an ardent admirer (wearing one) or as an astute trader of the same, one would need to be familiar with the four Cs color, cut, clarity and carat.
Color
With the naked eye, most diamonds would appear colorless, but they do have subtle shades of colors. Experts use the letter D (colorless) moving through all the letters all the way to Z (light yellow) in identifying them.
A colorless diamond is chemically pure and structurally perfect. It lets through most of the light (perfectly transparent) and produces the most amount of brilliance.
Most natural diamonds, however, are imperfect, and colorless diamonds are very rare.
It is, therefore, the most expensive of all.
The diamond color is produced by chemical impurities or structural defects in the stones crystal pattern. It causes a yellowish to brownish tint. However, blue or pink diamonds are also considered more desirable and command some very high prices as well.
Gemologists label diamonds with unusual or intense colors as fancy and they have their own rating systems, although it is not commonly used because of the relative rarity of such stones.
Cut
This is the most important of all the four Cs in assessing the stones beauty. Cut refers to the precise proportion and dimensions of a finished diamond. This is not to be confused with the stones shape (round, princess, marquise, pear, baguette, etc).
A diamond that had been cut properly allows light to enter and refract it, creating what is called brilliance. Cut too shallow or too deep, a stone will not properly refract the light and will look dull and lifeless.
A well-cut stone looks like it has greater carat weight, has more clarity and color. All in all, it appears to be of better grade than it actually is.
Clarity
Diamonds have natural imperfections called inclusions. These are minerals or crystals trapped inside the stone, and they determine the clarity of the stone.
Nearly all stones have characteristic inclusions (birthmarks) which make them unique and identifiable. These imperfections are graded accordingly and these also determine their value.
These are noted in the stones certificate from IF (internally flawless), VVS (very, very slight inclusions) all the way down to visible inclusions(I).
Carat
This is the measurement of a diamonds weight. One carat is 200 milligrams. The point unit (0.01 carat or 2 milligrams) is used on stones lesser than one carat.
Normally, the price per carat increases with carat weight because larger diamonds are rarer and desired. However, carat weights are not the final arbiter of value.
A smaller stone with better color and clarity commands a better price than a bigger one with poor color and clarity. Total carat weight (TCW) is used when referring to the total mass of stones in a piece of jewelry (bracelets, necklaces, earrings, multiple-stoned rings, etc.)
Your choice
Choosing the diamond jewelry of your dreams actually boils down on your attraction to a particular stone, maybe because of its color, brilliance or its shape. Knowing the four Cs is important, whether you are a layman or want to be an expert.