Understanding diamonds is an important part of what we do at Roger’s Jewellers and we want you to make an informed decision when purchasing your diamonds with us.
The 4 C's of Diamonds
Colour, shape, clarity and carat weight
determine the rarity and value of a
diamond, but the make determines its
beauty. Without any cutting, bruting,
faceting or polishing, a rough diamond
might very well go unnoticed in a pile of
rocks. It is the diamond's unique
combination of durability, rarity and
potential beauty that makes it so
The cut actually pertains to both the shape of the diamond and to the make (how well a diamond was fashioned to good proportions and polish). Shapes include round, marquise, princess, radiant, pear, oval, emerald,
and heart, and a few rare shapes.
The colour of diamonds varies from colourless (highest quality) to many shades of yellow (less rare). Some people ignore the "popular" trend toward the colourless and prefer the warmth of light yellow tints.
Diamonds are a natural substance, and no two diamonds are exactly alike. Nature signs each of its creations with telltale inclusions, or internal flaws. A diamond with more inclusions will be less rare, so it will be less expensive. But this does not necessarily mean it will be less beautiful to the naked eye.
The weight of diamonds is measured in carats. Larger diamonds are much more rare, so a 2-carat gem will be worth significantly more than 2 diamonds of the same quality weighing 1 carat each.
What do I need to consider when selecting my diamond?
The first step in choosing a diamond often involves selecting your favorite (or her favorite) shape. The Round Brilliant is by far the most popular shape, and it is the most readily available in every possible quality and size.
Contrary to popular belief and perhaps your experience in most stores, fancy-shaped diamonds (as all non-round diamonds are called) are often less expensive than their round brethren... at the wholesale level.
The Princess cut is becoming popular because it is both brilliant and unique. The Princess shape actually saves money for a cutter, since it is closest to the octahedral "habit" of rough diamond crystal, the most common formation of diamond in the rough. (The octahedron is like two pyramids base to base.)
Compared to a Round Brilliant, a cutter can retain more of the original crystal when cutting an octahedron into a Princess shape. The square corners of the rough need to be cut away to create a Round, but they are saved when cutting a Princess.
The more he saves of his original rough crystal, the less the cutter loses on his financial investment in the stone, and therefore you pay less as well.
But many shapes can be beautiful if they are cut well, including the Marquise, Oval, Pear, Radiant, Heart, Emerald and other major shapes. But all fancy shapes have an inherent difference in the physics of light. The longer shapes have a slight "bow tie" effect. This means they have a small zone in the center where light leaks out the bottom, creating a darker area in the shape of a bow tie. This is especially true for the Pear, Oval, Marquise, and Heart shapes.
Clarity is one of the two best-known factors in diamond pricing, along with colour. While the colour does affect a diamond's appearance, obvious inclusions (often called "flaws") may distract your recipient's eye from a stone's overall beauty. We usually recommend diamonds without inclusions or flaws that are visible to the naked eye. This avoids inadvertent negative feedback from friends and ensures the wonderful, lifelong enjoyment of your diamond.
Diamond weights are measured in "carats." One carat equals 1/142nd of an ounce, or 1/5th of a gram. In other words... there are 142 carats in 1 ounce and 5 carats in 1 gram.
The word "carat" comes from the ancient practice in India (where diamonds were first discovered and traded) of measuring diamond weights with the one thing in nature that is both small and the most consistent in weight -- the carob seed. Thus the name "carat" evolved in the English language, which is still equivalent to approximately the weight of one carob bean.
You also may have heard jewelers talking about "points" when discussing diamond sizes. This does not refer to the number facets on a diamond, but rather to its weight. Just like one pound is divided into 16 ounces, one carat is divided into 100 points -- so each point is 1/100th of a carat. A "10-point" diamond weighs 1/10th of a carat, and a 50-point stone weighs one-half carat.
Carat weight has a great deal of influence on the price of a diamond -- more so than one might imagine at first. Since larger stones are more rare in nature, they are more expensive as well. For instance, one diamond weighing 2 carats will always cost much more than two diamonds of the same quality weighing 1 carat each.
Below is an approximate comparison of the major diamond weights to act as a starting point in your consideration.
Colour, shape, clarity and carat weight determine the rarity and value of a diamond, but the make determines its beauty. Without any cutting, bruting, faceting or polishing, a rough diamond might very well go unnoticed in a pile of rocks. It is the diamond's unique combination of durability, rarity and potential beauty that makes it so valuable.