Origin of the Diamond 4Cs
Every diamond is a miracle of time and place and chance. Like snowflakes, no two are exactly alike.
Until the middle of the twentieth century, there was no agreed-upon standard by which diamonds could be judged. GIA created the first, and now globally accepted standard for describing diamonds: Color, Clarity, Cut, and Carat Weight. Today, the 4Cs of Diamond Quality is the universal method for assessing the quality of any diamond, anywhere in the world.
The creation of the Diamond 4Cs meant two very important things: diamond quality could be communicated in a universal language, and diamond customers could now know exactly what they were about to purchase.
Color - Diamond Color Actually Means Lack of Color
The diamond color evaluation of most gem-quality diamonds is based on the absence of color. A chemically pure and structurally perfect diamond has no hue, like a drop of pure water, and consequently, a higher value. GIA's D-to-Z diamond color-grading system measures the degree of colorlessness by comparing a stone under controlled lighting and precise viewing conditions to masterstones stones of established color value.
Clarity - Diamond Clarity Refers to the Absence of Inclusions and Blemishes
Natural diamonds are the result of carbon exposed to tremendous heat and pressure deep in the earth. This process can result in a variety of internal characteristics called 'inclusions' and external characteristics called 'blemishes.'
Evaluating diamond clarity involves determining the number, size, relief, nature, and position of these characteristics, as well as how these affect the overall appearance of the stone. While no diamond is perfectly pure, the closer it comes, the higher its value.
Cut - A Diamond's Cut Unleashes Its Light
Diamonds are renowned for their ability to transmit light and sparkle so intensely. We often think of a diamond's cut as shape (round, emerald, pear), but a diamond's cut grade is really about how well a diamond's facets interact with light.
Precise artistry and workmanship are required to fashion a stone so its proportions, symmetry, and polish deliver the magnificent return of light only possible in a diamond.
Carat - Diamond Carat Weight
Diamond carat weight is the measurement of how much a diamond weighs. A metric "carat" is defined as 200 milligrams.
Each carat can be subdivided into 100 'points.' This allows very precise measurements to the hundredth decimal place. A jeweler may describe the weight of a diamond below one carat by its 'points' alone. For instance, the jeweler may refer to a diamond that weighs 0.25 carats as a 'twenty-five pointer.' Diamond weights greater than one carat are expressed in carats and decimals. A 1.08 carat stone would be described as 'one point oh eight carats.'
Diamond, which is solely composed of the element Carbon, is the hardest substance known to man. Diamonds were formed many millions of years ago more than one hundred miles below the earths surface. The Diamonds, still in their rough crystal form were carried to the earths surface in molten lava which then hardened. Over time the forces of erosion moved some of these Diamonds around, which explains why they are found in rivers and streams, often very far from their original source of creation. Diamonds are mined from the hardened lava "Diamond Pipes" and removed from the surrounding rock, which is called "Kimberlite". The process of panning and digging river beds is known as alluvial mining. Many times rich alluvial deposits are found in pockets, that have washed away the lighter Kimberlite, leaving a high concentration of Diamond rough.
After Diamonds are mined they go through many hands, where they are sorted, graded and packed in boxes called "Sights" to be sold to a very select group of diamond dealers called "sight holders". These dealers are either cutters or buying to sell the rough Diamonds to other cutters. It is the cutter that unlocks the Diamonds inner beauty, and brilliance. Diamond cutting is truly an art, the cutter must make a decision which balances how to retain the most weight from a piece of rough, while at the same time cutting one or more stones which will yield the greatest value based upon there finished sizes, clarities, colors and shapes. The cutter must be able to envision the finished product before he starts his work.
The next step in the life of a Diamond is selecting a setting that will enhance the beauty of the Diamond. Then a Diamond is ready for the jewelers showcase. Of course, many diamonds are sold un-mounted as well.
THE FOUR C's: Factors that determine the value of a Diamond
The four C's are a Diamond grading system developed by Gemological Institute of America (G.I.A.) which is widely used in the jewelry industry today. The four C's are Carat, Clarity, Color and Cut. The combination of these factors determines the relative quality and value of a Diamond.
CARAT: A Carat is an extremely exact unit of weight measurement which is divided into one hundred smaller units called "points". A Diamond that is half a carat would weigh fifty points. Some extremely delicate jewelers scales will even weigh in fractions of a point. To give you a comparison, a point in weight is approximately equivalent to 1/15,000th of an ounce!
CLARITY: Clarity refers to the internal characteristics of a Diamond as seen by a trained eye through a ten power corrected lens. A hand held ten power corrected lens is known as a "loupe" or eye-loupe. There are eleven clarity grades in the G.I.A. system of grading. A clarity grade is assigned based on the size, location, and amount of "inclusions" or natural imperfections in the Diamond. In the case of a flawless Diamond the clarity grade of flawless would actually be assigned on the basis of the absence of any imperfections. The eleven clarity grades, in descending order of quality, are as follows:
IF (INTERNALLY FLAWLESS)
VVS1 (VERY VERY SLIGHTLY INCLUDED)
VVS2 " " " "
VS1 (VERY SLIGHTLY INCLUDED)
VS2 " " "
SI1 (SLIGHTLY INCLUDED)
SI2 " "
I1 ( IMPERFECT)
There is currently an SI(3) grade being used by many suppliers and jewelers but it is not acknowledged by the G.I.A.
COLOR: The color of a Diamond is actually the body color and not the colors you see coming out of a Diamond. The term "blue-white" Diamond is a misnomer, it is not a color grade, but instead it refers to the blue and white light that is reflected and refracted from a Diamond. Diamonds that are totally colorless (white), reflect white light and refract some ofthe light that enters into the Diamond back through the crown facets to the viewer in the colors of the spectrum. Lighting other than true white light that does not contain all of the colors of the spectrum will change the way a Diamond appears. Incandescent lighting tends to make Diamonds appear yellow because the blue colors of the spectrum are missing. When all colors of the spectrum are present, a colorless or near colorless Diamond will display a lot of blue and white light, hence, the association of the term blue-white with better quality Diamonds.
Diamonds are found in a range of colors, from faint yellow or brown through to the very rare pinks, blues, greens and other colors known as "fancies". The difference between one color grade and another color grade can be very subtle, and explains why there are a number of grades within any one category. The color grading system uses the letters D to Z to describe a Diamonds color. The G.I.A. categories for color, in descending order of quality are listed below;
G,H,I,J: (NEAR COLORLESS)
K,L,M: (FAINT YELLOW)
N,O,P,Q,R: (VERY LIGHT YELLOW)
S,T,U,V,W,X,Y,Z: (LIGHT YELLOW)
Truly colorless Diamonds are composed of pure Carbon. Color in a Diamond is the result of the trace elements which are present when the Diamond is formed. Diamonds thathave formed with Nitrogen, an abundant element, in their crystal structure, are yellow. Blue Diamonds, which are very rare, require Boron, a very rare element, to be present when formed.
CUT: The cut of a Diamond refers to the physical proportions and finish of the Diamond and should not be confused with the shape of a Diamond. The cut of a Diamond is often referred to as the "make" by dealers and jewelers.
The polished surfaces, which are known as the "facets", of a well polished Diamond will look like mirrors. The proportions of a Diamond are the key to how much light will enter and then be reflected back out of the Diamond. The finish is how well a Diamond is polished.
There are "ideal" proportions that will optimize the amount of light going in and out of a Diamond. Diamond cutters try to stay close to these ideal proportions but must also consider the possibilities of excessive weight loss. A cutters goal is to strike a balance which will yield the greatest value and best appearance for a finished Diamond. When you look at a Diamond "face-up", or through the large table facet, you see several kinds of light. Some white light is reflected off the external surfaces and some of the light that enters a Diamond is refracted and reflected out, in the colors of the rainbow, this is known as "dispersion". When you move a Diamond the light reflects and refracts off the facets creating a flashing effect known as "scintillation".
THE PARTS OF A DIAMOND
THE FACETS OF A DIAMOND
TOTAL AMOUNT OF FACETS 58
STAR FACETS 8
BEZEL FACETS 8
UPPER GIRDLE FACETS 16
LOWER GIRDLE FACETS 16
PAVILION MAINS 8
Afull cut Diamond has 58 facets. A single cut Diamond is one in which there are 16 facets, and is a common cutting style in Diamonds up to about five points in size. Occasionally a cutter will find the need to remove an inclusion near the surface or to compensate for facets which do not meet correctly and he will add an "extra facet". Extra facets have no effect on clarity grades.
The girdle of a Diamond is not a facet, but it is sometimes polished or facetted. An unpolished girdle is often referred to as a "frosted girdle". The girdle thickness is a primary indicator of how well a diamond is cut. A heavy girdle occurs when the cutter puts more emphasis on retaining weight. If a girdle is made to thin, it may cause the edges of a Diamond to chip relatively easily. The shape of a well made girdle becomes narrower and then wider as you rotate the Diamond due to the flat facets meeting on the round edge. Girdle thickness is described as; Very Thick, Thick, Medium, Thin to Medium, Thin, Very Thin.