Diamonds are formed from ordinary carbon; it was once the same as the lead in your pencil. Over billions of years the carbon crystalized into a diamond — just as water crystalizes to a snowflake and sugar crystalizes to rock candy.
Every diamond is created uniquely. The terms used to describe the different characteristics for each diamond are:
- Shape, Size, Clarity, Color, Cut, Brightness, Fire, Sparkle, Polish, Symmetry, Fluorescence, Luster.
Raw diamonds, mined from the earth, are cut and polished into various shapes. Shape refers to the view from the top. Choosing your shape is a matter of preference.
"Shape" and "cut" are different but often confused for each other. The terms describe different characteristics of a diamond. Shape is the view from the above; cut is its view from the side.
Round, sometimes called round-brilliant, is the most popular shape, followed by square shape. The popularity of diamond shapes can be trendy; however, round is classic and stands the test of time. The next most classic shape are square and cushion shapes. Shapes that are more unusual will only look proper with certain ring designs.
Diamonds weights are measured in "carats" or "points" before to being set into jewelry. Carats and points are units of measure, like pounds or ounces. "One carat" equals the weight of 1/5 of a gram.
Carat (spelled with a 'C') can be confused with karat (spelled with a 'K'), which refers to the percentage of gold content, such as "fourteen-karat-gold".
A one carat diamond equals 100 points — just as one dollar equals 100 cents. So, a 1/4 carat diamond has approximately 23 points to 28 points, and a 2 carat diamond has exactly or near 200 points, and so on. A diamond's carat weight does not always relate to its size.
That's because unleashing the beauty from within a diamond, requires cutting away valuable weight from the very bottom of the raw stone. If this "extra" weight is not trimmed off you'd end up paying for weight that doesn't make the diamond look larger, plus detracts from its beauty. It's like a butcher who sells you a steak without trimming the fat.
It's like the difference between quantity vs. quality. Diamonds should be compared by their diameter (or dimensions viewed from the top), not its weight.
Obviously, the larger the diamond are, the more costly per unit of weight.
A 1/2 carat diamond that sells for $2000 would sell for about $8400 if it were a one carat with identical characteristics.
Clarity describes the natural birthmarks that formed within the diamond as the carbon into a diamond crystal. Think of a diamond’s clarity like a fingerprint. Each diamond is unique and can be identified by its natural markings even though it requires a microscope. These various markings inside and on the surface of a diamond can look like black specks or lines, white specks or lines, bubbles, cracks, or clouds.
Do not choose a diamond based on what you see under the microscope. Markings that are easily seen under a high quality microscope are often times are not visible to the un-aided eye. Only view diamonds placed side-by-side next to the highest clarity diamond available; with many diamonds, you won’t see a difference even when examined at very close range without magnification.
Gemologists determine clarity by measuring the size, location, quantity, type, and prominence of the “blemishes” in accordance with the GIA’s standards. With the exception of I1*, I2*, and I3*, and sometimes SI2*, a diamond’s clarity does not determine its beauty; the function of clarity is to group the diamond according to its rarity. Do not choose your diamond by selecting a particular clarity grade. Two diamonds with same grade may not look the same. A "high" SI1 has a very different monetary value than a "low" SI1.
Diamonds form in nature in different colors. It’s best not to think of these colors as red-like-a-ruby or blue-like-a-a-sapphire. The differences in color are very subtle. Color variation is more like the difference between crystal clear spring water and lemonade. Some diamonds lack any tint or body tone and are clear like icy spring water. Icy "white" diamonds have the perfect backdrop for displaying the inner blaze that result from a diamond’s unique optical properties. Diamonds with tinges of yellow (or brown or grey) look as if a glass of water had drops of lemon squeezed in until it became lemonade; this more saturated color mutes the powerful inner-blaze.
Of course, the whiter ones are brighter. But if you kept squeezing in lemon until the diamond becomes intense yellow then they become even more valuable than the whitest ones. That's because super-saturated colors are much scarcer than icy white ones and classified as fancy-colored.
With fancy colors, the intensity of its color is as important as the diamond’s brightness.
Choose the highest color as you can afford in the size you're hoping for. "High color" refers to "absence-of-color" since the best color is a lack of any color. Color, or shades, are usually yellow but can also be brown or grey. "Color" refers to something completely different, yet interactive with a diamond’s "fire", which refers to a diamond's unique ability to bend light like a prism producing brief inner flashes of reds, blues, and greens.
The highest color grade in the GIA scale is "D color" and goes down to "Z". The scale begins with "D" instead of "A" to avoid confusion with the many competing color-grading scales that were already in existence prior to 1953 when the GIA introduced its system. Gemologists grade color by comparing each diamond, placed upside down on its table (top surface), to a set of master comparison diamonds in a predetermined standard lighting and viewing environment to determine its color.
Cut describes the design and workmanship of transforming a "raw" diamond from the earth, into a vibrant gemstone. How a diamond is cut, or designed, accounts for its Brightness, Fire, and Sparkle and all three characteristics are incorporated in the cut grade. Distinguishing these three different characteristics of how light interacts with a diamond is possible when viewing diamonds, in person, side by side. Choosing which characteristic is most pleasing to you is about your taste and what pleases your eye. You may prefer diamonds with a cut grade of Very Good over one graded Excellent –and that’s perfectly fine. Diamonds with a cut grade of Good, Fair, and Poor are usually not preferred.
Brightness, often called brilliance, is the level of light radiating up from within and off the surface of the diamond. When a ray of light reaches and passes through the surface of a diamond, it bends like a light ray passing through a prism. But with a diamond, the light bends even more than in a prism because they are so dense. Once inside the diamond, as the light ray continues on its path, then bending two more times completing a U-turn so that the light ray returns a shower of brightness and fire back toward your eye but only if cut with a proper silhouette. Lacking a proper silhouette, light will bend upon entering the diamond’s surface, but some light will escape through the side and bottom of the diamond and fail to complete the U-turn, causing less brightness and less of the rainbow-like fire that results from each bend.
Why don't all diamonds have a this desirable silhouette? It’s due to what is called weight-ratio. Weight–ratio is the relationship between the diamond size (when viewed from the top) and its weight. Almost all raw diamonds are mined from the earth with a silhouette that is too deep. So think of the diamond cutter just like a butcher who must trim away fat from a piece of steak. For example, if a raw diamond is cut into a round shape and has a diameter of only 6 mm then its proper design would be as a ⅞ carat with a lean under-belly and a proper silhouette. If the underbelly "fat" were not removed, the 6 mm diamond would end up the wrong weight-ratio. It would weigh one carat but only look like a ⅞ carat diamond lacking beauty. In order to unleash a high level of brightness the cutter must slice away slabs from its "belly", to steer light in a desirable U-turn
Fire, also called dispersion, describes the colors-of-a-rainbow that appear in a diamond. Diamonds behave like prisms but since its shape is different than prisms the colors don’t appear in straight rows but more like shards of color as in a kaleidoscope. As a diamond moves the shards of colors change like in a kaleidoscope, so you see only see fire in different lighting conditions, from different viewing angles. You also must view the diamond from a distance of over three feet because when viewed from up close the chards of color change to shards of white light.
Sparkle, sometimes called scintillation, describes the twinkling effect given off as diamonds move about, as if there are white flashes of fireworks within the diamond. The sparkle, or flashes-of-light, come from rays of light reflecting off the diamond’s multiple surfaces. Your eyes "notice", or perceive, the flashes when there is sufficient contrast of dark areas within the diamond just as stars against the dark night are lost in the daytime. All diamonds some amount of these flashes however multiple mini-flashes are more beautiful than one big blast blaring like a headlight. The pattern of sparkle should be evenly spread out in a field of "stars" rather than a blotchy array.
Polish is the quality of a diamond's surface. Diamonds have many polished surfaces, called facets. The facets resemble either a triangle or a stretched or contorted kite. Due to diamond's extreme hardness, creating a mirror-like finish on each surface is achieved after long and painstaking grinding then polishing. Even if it takes a microscope to see the tell-tale parallel or circular lines that result from an improperly polished diamond, if not eliminated, they will interfere with the luster, or "pop", that comes from light reflecting off its surfaces. These individual surfaces must join invisibly, with seamless edges, so that the diamond appears as a solid monolith. Polish is an important factor in a diamond’s beauty but a grade of Very Good may result from "deductions" that are visible under a microscope but do not affect the visual beauty of the diamond.
Symmetry describes the how perfect the facets align. Perfectly aligned facets appear more beautiful. Symmetry also describes how perfect the shape is. For example, if the diamond is supposed to be round, is there a flat spot along the circle or a perceptible oval shape to the circle? The workmanship to create excellent symmetry takes time, care, planning & attention to detail. The GIA symmetry grades are Excellent, Very Good, Good, Fair, and Poor. Trust your eye and your judgment. A grade of Good or Very Good may look visually perfect to you because there can be symmetry "deductions" that are visible under a microscope that do not affect the visual beauty of the diamond.
Fluorescence describes the "glow-in-the-dark" effect diamonds emit when exposed to invisible ultraviolet (UV) rays. The sun emits these UV rays. Grading certificates measure the strength, or intensity, of the diamond's fluorescent tendencies but do not address whether the diamond's beauty is affected.
For almost all fluorescence diamonds with faint fluorescence, its fluorescence does not affect its beauty however when a diamond has medium in fluorescence, it's beauty can be affected. For diamonds with strong or very strong fluorescence it's important to view the diamond in strong sunlight because it may appear hazy or oily and undesirable. The price of diamonds are lower the more fluorescence it exhibits.
Diamonds are the hardest material in the world but that doesn’t mean they can't break or chip. Hardness is simply the resistance to scratching. In fact, when a diamond cutter splits a raw diamond crystal into two pieces sometimes it takes only a tap in the right spot to break it in two. Therefore, it is important to cut a diamond so that its outer edge, called its girdle, is not too thin. Otherwise the girdle may be exposed and susceptible to getting chips. Equally important is the tiny facet on the bottom called the 'culet', that looks as if it's a point but in fact it’s a small flat surface. Under a microscope some diamonds can be observed without a culet and actually do come to a point. This is a signature of a diamond cutter's masterful expertise, though this type of diamond must be handled by expert diamond setters, so the point is not damaged. Also, the corners of some fancy shape diamonds come to a point requiring the skills of highly experienced diamond setter when secured into a ring.
Diamonds have an extremely important quality characteristic that is not included on diamond certificates called luster. It describes the "pop" of the diamond. Differences in luster are due to the formation of the diamond’s crystal structure. Think of two pieces of maple wood where one has smooth even grain and another has knots with wavy grain. Diamonds with a poorer crystal structure appear dull, oily, or greyish. Diamond can have a respectable GIA grade but be missing "the bling". A proper crystal structure results in a vibrant, powerfully brilliant stone. The way to ensure that your diamond has excellent luster is by viewing the diamond in person. You cannot determine luster from a GIA certificate or an online image.