The Diamond world is quite orderly. Diamonds are graded on sliding scales to enable us to assign specific grades to the stone. The stones are assessed on the following factors:
This refers not only to the shape of the gemstone but also to the proportions and angles the diamond has. A stone that is correctly proportioned will return more light to the viewer making the stone "pop" when you look at it. Today the industry is becoming inundated with branded diamonds based on the diamond's cut. A term you may often hear is "ideal cut." This refers to stones with proportions that fall within certain parameters. The table is usually less than 58% of the total diameter of the stone, and the depth percentage (the relationship between the depth of the stone and the diameter) falls within the 60.5% - 62% range. Also the symmetry of the stone will be such that all the facets point to each other, will all being similar in shape around the stone, and the top of the stone and bottom of the stone will align in their faceting arrangement.
Cut is very important. A stone that is well proportioned will, ideally, have all the light that enters into the stone, totally internally reflect within the stone, and exit through the top or crown of the stone giving the stone brightness when viewing.
Color is the actual body color of the diamond. Most diamonds have a slight tint of yellow or brown while others are called "fancy colored" - those diamonds that are blue, pink, canary yellow, green, or cognac colored. Those diamonds that have no tint of yellow or brown are the most valuable diamonds. The Pink and Blue diamonds are the more expensive of the Fancy colored diamonds.
The color grades are rating on an alphabetical scale from D to Z.
Diamonds that are in the D, E, F, and even G grade, are inherently bright. The spectral colors, or sparkle, are very true because there is no body color to impair them. H, I, and J are in the near colorless range meaning that, to most people they cannot discern a body color but the stone may have a slightly "warmth" to it. J is actually the average color grade. Once the stone goes into the K range, most people can see that the stone has a yellowish tinge.
This refers to the amount of inclusions or clarity characteristics within the diamond itself. For most grades, the characteristics are only visible with the ten power (10X) microscope or loupe. The theory of clarity grading is that the more inclusions there are in a stone, the less rare it is and the more inclusions there are to interfere with light passing through the stone. Inclusions are internal characteristics, blemishes are surface characteristics.
We use a scale to measure the actual, carat weight of the diamond. The carat is 1/5th of a gram. A carat is divided into 100 points. A .50 carat diamond is 50 points, 50% of a carat, or a half carat diamond. Likewise, a .75 carat diamond is 75% of a carat or a three quarter carat diamond.
Flawless - nothing visible under the microscope.
Internally Flawless - the stone may have a blemish, such as a scratch or polishing line. We don't see many of these stones in rings because a little knock could cause the clarity grade to lower.
VVS 1, VVS 2 - Very very slightly included means that under the microscope it is very difficult to find the one or two very small inclusions.
VS 1, VS 2 - Very slightly included stones have an inclusion that is slightly easier to find under 10 power magnification - usually more in the center of the stone than on the sides.
SI 1, SI 2 - Slightly included diamonds have inclusions that are somewhat easy to see under the 10 power microscope. They are not usually visible to the unmagnified eye unless the stone is over 2 carat. SI diamonds would be considered the average in diamond clarity grades.
I 1, I 2, I 3 - these stones have inclusions visible to the unaided eye that may or may not affect the beauty and durability of the stone. There are many very good I 1 stones that a Gemologist would have a harder time seeong the inclusion.
Diamonds are priced per carat. The larger the diamond, the rarer it becomes so the price per carat is higher for a one carat diamond of a certain grade, than it would be for two, similarly graded, - caratsers (.50 each) because a 1 carat is rarer than two .50 pointers. At certain "magic sizes" the price per carat goes up. This occurs at .25, .33, .50, .66, .75, .90, then in increments of one half carat.
We have Graduate Gemologists on staff that grade our diamonds as well as offer stones with reports from independent laboratories. The Gemological Institute of America (GIA), and the American Gem Society (AGS) labs have highly regarded reports in the industry.
Diamond is the hardest, natural substance with a 10 in hardness on a scale from 0-10. Hardness is the resistance to scratching. Toughness is the resistance to chipping and breaking. Diamond has four directions of perfect cleavage. Much like a piece of wood can easily be split along the grain, diamond has four such "grain" directions. By using these cleavage directions the cutter can easily sheer off areas of the rough that are highly included.
Many countries in Africa combine to produce about 65% of the diamonds today, by value. Botswana, South Africa, Namibia, are all larger producers. Russia, in cold Siberia, produces another 20% of the diamonds. But, did you know that Canada produces approximately 10% of the world's diamonds by value. Yes, the great white north has more than one type of ice. We can get Canadian diamonds if you are looking for a North American Pedigree for your stone. Australia produces the most carats of diamonds in the world. If you've seen pink diamonds, this is the source. If you've seen champagne and cognac diamonds, these too are usually an Australian stone. For the most part, Australia produces the small, colored diamonds you often see in inexpensive tennis bracelets.