The factors which can affect the colour of the diamonds are fluorescence, high temperature treatment and irradiation. Fluorescence is the referred to as the intensity of the diamond to give off a blue colour when exposed to ultraviolet light.
Clarity in diamond is a measure of the surface and internal characteristics of a polished diamond. To find out the clarity of the diamonds light are being passed through it. The more the light passes optimally, the better the clarity is. Since nothing in nature is perfect, therefore finding a diamond with perfect clarity is also very rare. However, if a diamond being magnified at 10 times the normal view shows no inclusions, it is considered flawless, or as close to perfect as possible.
The unit of diamond is called carat. 1 carat is equal to .2 grams or .007 ounces. The weight of diamond is directly related to its size. Since diamonds are so small and light, carats are broken down into decimals called points, with 100 points in each carat. Most of the common sizes of diamonds in jewellery range from .01 to 3 carats.
Cut of the diamond is very important because of the 4C’s, the cut is the aspect directly influenced by man. The other three are directed by nature. A well-cut and well-proportioned diamond allows the maximum amount of light to enter, reflect and return to the observer’s eye. Variations of good proportions show light leaking out of the diamond, which lessens the value of the stone. The clear reflection of light and sparkle value are called the fire of the diamond. If a diamond is cut the wrong way or along improper inclusions lines, the stone can lose a lot of its original value, which is why having a talented and experienced jeweller cutting it is so important.
In 1919, Marcel Tolkowsky calculated the most ideal cutting angles and proportions for diamonds to allow the best balance dispersion or distribution of light and brilliance. Some of the most essential factors Tolkowsky believed important were the Star facet, Bezel facet, Upper Girdel facet, and the centre table of each diamond.
There are nine traditional shapes and cuts of diamonds, including the round, marquise, emerald, princess, pear, oval, heart, baguette and trillion. The most popular cut for diamonds today is still the Round Brilliant Cut, which is famous for engagement rings and make up 75% of all diamonds sold. The average price for a single carat diamond with reasonable 4C qualities ranges between about $1,900 and $17,000. Qualified jewellers do not recommend one-carat diamonds that are cheaper than this since they will probably not have very good 4C qualities and less resale for customers wanting to upgrade in the future.
Cut and cutting style must both be equally expert to form a diamond with strong brilliance for reflecting light. There are three categories of cutting style, such as step-cut, brilliant-cut, and mixed-cut. The facets in each show the difference between these three types of cuts. The facets are the edge of the stone that is cut into the diamond.
Step-cut diamonds like Emeralds or Banquettes have rows of facets that look like the steps of a staircase because they are elongated and four-sided. Mixed-cut diamonds have both Brilliant-cut and Step-cut facets in them. Some Mixed-cut diamonds include Radiants, which are rectangular or square shaped stones with step or scissor-cut on the crown and Brilliant-cut on the pavilion. Barion Mixed-cut diamonds were the first square stone on the market with a traditional Step-cut crown and an altered Brillian-cut pavilion with 62 facets. The largest diamond in the world is the Millennium Star, which has 777 carat.
So in short the 4Cs method of evaluating diamonds helps you to determine the best qualities of the stones. Hence each feature of the 4Cs method is essential to a diamond’s value. So next time when you go to purchase diamonds for yourself or your loved ones don’t forget to evaluate the diamond by the 4Cs method.
