Most people think that gem quality diamonds are colorless, but the truth is that truly colorless diamonds are very rare. Most diamonds used in jewellery are nearly colorless with tints of yellow or brown. Diamonds are compared to a master set to determine the color grade for a particular stone. A letter grade scale is used ranging from D to Z, with D being Colorless and Z being light yellow or brown.
Due to how diamonds are formed, under extreme heat and pressure, it extremely rare to find a diamond that is internally and externally flawless. Most diamonds have some internal ‘characteristics’ which are a by-product of its formation. These characteristics help gemologists separate natural diamonds from synthetics and simulants, as well as helping to identify individual stones.
The GIA Cut Scale ranges from Excellent to Poor. Many people think that the ‘cut’ of a diamond is referring to its ‘shape’, but in actuality, a diamonds cut grade is really about how well a diamond's facets interact with light. A polished diamonds beauty lies in its complex relationship with light. There are three attributes that make up the magnificent display you see in a diamond; Brightness, Fire, and Scintillation.
- Brightness – is the combination of all the white light reflecting from the surface and interior of a diamond
- Fire – describes the ‘flares’ of color emitted from a diamond
- Scintillation – describes the pattern of light and dark areas and the sparkle you see when the diamond, the light, or the observer moves. A diamonds proportions greatly affect its light performance, which in turn affects its beauty and appeal
Diamonds with fine proportions, symmetry, and polish optimize this interaction with light and have increased brightness, fire, and scintillation. These factors are assessed for standard round brilliant diamonds.
One carat equals 200 milligrams in weight. For diamonds under one carat, each carat is divided into 100 points, similar to pennies in a dollar. ¾ ct. = 75 points, ½ ct. = 50 points.
Please use this interactive tool to learn more about the 4 C’s of Diamonds and how each diamond is graded.
Diamonds can be cut and polished into many shapes. Below are the 10 most popular shapes.
The round cut diamond is the most popular diamond shape, representing approximately 75% of all diamonds sold. Due to the mechanics of its shape, the round diamond is generally superior to fancy diamond shapes at the proper reflection of light, maximizing potential brightness. Virtually all round diamonds are brilliant-cut, meaning they have 58 facets.
The princess cut diamond, is the most popular fancy cut, especially for engagement rings. Like round cut diamonds, princess cut diamonds are a good choice for their flexibility in working in almost any style of ring. Princess cut diamonds also tend to have a slightly lower price-per-carat than round cut diamonds. Of all of the square cuts, the brilliant-cut princess (along with the radiant cut) comes the closet to achieving the fire and brilliance of a round diamond, making it an ideal combination of unique shape, sparkling appearance, and relative price value.
The unique look of the emerald cut diamond is created by the step cuts of its pavilion and its large, open table. Instead of the sparkle of a brilliant-cut, emerald cut diamonds produce a hall-of-mirrors effect, with the interplay of light and dark planes. While less fiery, the long lines and dramatic flashes of light give the emerald cut an elegant appeal. The shape was originally developed for the cutting of emeralds, thus the name.
The modified brilliant-cut pear shaped diamond is a combination of a round and a marquise shape, with a tapered point on one end. The diamond is always worn with the narrow end pointing toward the hand of the wearer. Like marquise and oval cuts, the pear shaped diamond comes in a variety of slim to wide cuts, and has the added benefit of making the wearer's fingers appear longer and slimmer.
The radiant cut diamond is the first square cut (the second being the princess) to have a complete brilliant-cut facet pattern applied to both the crown and pavilion, creating a vibrant and lively square diamond. First popular in the 1980's, the cropped corner square shape of the radiant is a nice bridge between a cushion and a princess cut, and for that reason looks beautiful set with both rounded or square cornered diamonds.
The football-shaped marquise diamonds are a modified brilliant-cut. The name is derived from the Marquise of Pompadour, for whom King Louis XIV of France allegedly had a stone fashioned to resemble what he considered her perfectly shaped mouth. Because marquise diamonds are long and narrow, they can also create the illusion of greater size. Carat for carat, the marquise diamond has one of the largest crown surface areas of any diamond shape, making it a good choice when trying to maximize the perceived size of a diamond. Like the oval diamond, the marquise cut diamond's elongated shape can make the finger of the wearer appear longer and slimmer.
The cushion cut diamond once referred to as old mine cut) combines a square cut with rounded corners, much like a pillow (hence the name). This classic cut has been around for almost 200 years, and for the first century of its existence was the most popular diamond shape (similar to round cut today). Until the early 20th century, the cushion cut diamond was the de facto diamond shape. Traditional cushion cut diamonds return light in a chunkier pattern than modern cuts. Combined with the enlarged culet (which was considered desirable for the pattern created when viewed through the table), this created a distinctive look that is prized today among dealers in antique diamonds.
The modified brilliant-cut heart shaped diamond is a unique and unmistakable symbol of love. Heart shaped diamonds are very popular in solitaire pendants as well as rings. When choosing a heart, symmetry is a very important characteristic, since it is critical that the two halves of the heart are identical. The cleft (between the two lobes) should be sharp and distinct, and the wings (the sides as they curve down to the point) should have a very slightly rounded shape. Heart shaped diamonds of less than .50 carats may not be a good choice, as the heart shape is more difficult to perceive in smaller diamonds, especially after they are set in prongs. For smaller hearts, a bezel or three prong setting (one prong on each lobe, one prong at the point) will better preserve the heart shape outline of the diamond after it is set.
Created by Lazare Kaplan in the 1960's, oval diamonds are a modified brilliant-cut (like virtually all round cuts). Because the two shapes possess a similar fire and brilliance, the oval is an ideal choice for a customer who likes the look of a round diamond, but wants something more unique. Oval diamonds have the added advantage of an elongated shape, which can create the illusion of greater size. The slender shape can also make the finger of the wearer appear longer and slimmer, an effect often desired.
The asscher cut diamond was first produced in 1902 by the Asscher Brothers of Holland, famous at the time for cutting the world's largest rough stone (the Cullinan, at 3,106 carats). Asscher cut diamonds originally peaked in popularity in the 1920's, and could recently be found only in antique jewelry shops. Around 2002, one hundred years after the first asscher cut diamond was created, the shape began to make a comeback, spurred on by cut modifications that gave the shape more brilliance than traditional asscher cut diamonds. The modern asscher cut diamond is similar to a square emerald cut, usually with larger step facets, a higher crown, and a smaller table. This combination often produces more brilliance than the emerald cut. A well cut asscher will appear to have concentric squares as you look down through the table, the result of proper positioning of the pavilion facets underneath. Like the emerald cut, the asscher cut has cropped corners; however, because an asscher is square, the cropped corners give the asscher cut a somewhat octagonal shape. Once mounted in a four prong setting, the diamond maintains its unique shape within a square silhouette.