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Diamond is a crystalline form of carbon. Its rarity makes it extremely valuable and precious. The combination of the 4Cs, namely Carat, Color, Clarity and Cut, determines the value of a particular diamond.

Because diamond is the most hardness naturally found materials, it is ideal for both jewellery and industrial purposes. Fewer than 20 percent of the diamonds mined each year are suitable for making jewellery.

To discern the value and quality of a diamond, experts examine each of the Four Cs - Cut, Clarity, Carat and Colour.

   
Carat
Diamonds and other gemstones are weighed in metric carats: One carat is equal to 0.2 grams, about the same weight as a paperclip. (Don’t confuse carat with karat, as in “18K gold,” which refers to gold purity.) Carat is divided into 100 points. For example, a 50-point diamond weighs 0.50 carats.


1 carat =1.00 carat=100points
1/2 carat= 0.50 carat= 50 points
1/4 carat=0.25 carat= 25 points


Because even a fraction of a carat can make a considerable difference in cost, precision is crucial. In the diamond industry, weight is often measured to the hundred thousandths of a carat, and rounded to a hundredth of a carat. Diamond weights greater than one carat are expressed in carats and decimals.
   
Color
Diamonds are valued by how closely they approach colorlessness – the less color, the higher their value. (The exception to this is fancy-color diamonds, such as pinks and blues, which lie outside this color range.) Most diamonds found in jewelry stores run from colorless to near-colorless, with slight hints of yellow or brown.


Color-grading scale for diamonds begins with the letter D, representing colorless, and continues with increasing presence of color to the letter Z, or near-colorless. Each letter grade has a clearly defined range of color appearance. Diamonds are color-graded by comparing them to stones of known color under controlled lighting and precise viewing conditions.

Many of these color distinctions are so subtle as to be invisible to the untrained eye. But these slight differences make a very big difference in diamond quality and price.
   
Clarity
Because diamonds formed deep within the earth, under extreme heat and pressure, they often contain unique birthmarks, either internal (inclusions) or external (blemishes).

Practically all diamonds contain naturally occurring internal characteristics called inclusions. The size, nature, location and amount of inclusions determine a stone's clarity grade and affect its cost. Clarity is determined using 10X magnification. By definition, if something is not visible at 10X, it does not effect the clarity.


Diamond clarity refers to the absence of these inclusions and blemishes. Diamonds without these birthmarks are rare, and rarity affects a diamond’s value. Using the GIA International Diamond Grading System™, diamonds are assigned a clarity grade that ranges from flawless (FL) to diamonds with obvious inclusions (I3).

Every diamond is unique. None is absolutely perfect under 10× magnification, though some come close. Known as Flawless diamonds, these are exceptionally rare.
   
Cut
Cut is the critical factor for a diamond’s fire, sparkle and brilliance.

The traditional 58 facets in a round brilliant diamond, each precisely cut and defined, are as small as two millimeters in diameter. But without this precision, a diamond wouldn’t be nearly as beautiful. The allure of a particular diamond depends more on cut than anything else.

Though extremely difficult to analyze or quantify, the cut of any diamond has three attributes: brilliance (the total light reflected from a diamond), fire (the dispersion of light into colors of the spectrum), and scintillation (the flashes of light, or sparkle, when a diamond is moved).

An understanding of diamond cut begins with the shape of a diamond. The standard round brilliant is the shape used in most diamond jewelry. All others are known as fancy shapes. Traditional fancy shapes include the marquise, pear, oval and emerald cuts. Hearts, cushions, triangles and a variety of others are also gaining popularity in diamond jewelry.

As a value factor, cut refers to a diamond’s proportions, symmetry and polish. For example, look at a side view of the standard round brilliant. The major components, from top to bottom, are the crown, girdle and pavilion. A round brilliant cut diamond has 57 or 58 facets, the 58th being a tiny flat facet at the bottom of the pavilion that’s known as the culet. The large, flat facet on the top is the table. The proportions of a diamond refer to the relationships between table size, crown angle and pavilion depth. A wide range of proportion combinations are possible, and these ultimately affect the stone ’s interaction with light.
   
  • Brilliant Cut

    Brilliant Cut

    The most popular is round brilliant cut, its ideal proportion is designed to give maximum scintillation, brilliance and fire. For almost 100 years, diamond cutters have been using advanced theories of light behavior and precise mathematical calculations to optimize the fire and brilliance in a round diamond. It comprises of 58 facets, round brilliant cut follows more naturally the rough diamond crystal shape, and is the most readily available in every possible quality and size.
  • Princess Cut

    Princess Cut

    The princess is one of the most popular fancy diamond shapes. Its beautiful brilliance and unique cut makes it a favorite for engagement rings. The proportions are considered better the more square the stone is cut, with exact 90 degree internal angle on each corner; princess cut diamonds can also be slightly rectangle in shape.

    Optimum Shape is: Length to Width ratio 1:1
    Acceptable are: Length to Width ratio 1-1.4:1
  • Oval Cut

    Oval Cut

    An oval diamond has beautiful brilliance that's similar to a round diamond if well proportioned which gives great scintillation and fire. Oval diamond is also very popular as its length can accentuate long, slender fingers. A well cut oval diamond can be almost as bright as a well cut Brilliant or round shaped diamond as the angles for cutting are closer to that of a brilliant cut diamond.

    Optimum Shape is: Length to Width ratio 1.5:1
    Acceptable are: Length to Width ratio 1.5-1.75:1
  • Heart Cut

    Heart Cut

    The heart is the universal symbol of love. The unique look of the heart-shaped diamond makes it a distinctive choice for a variety of diamond jewelry. The heart shape is one of those special cuts that follow more human and emotional values. The technical benefit is that a heart shape diamond has a roundish pavilion and if well cut and proportioned can drive the sparkle and scintillation back out of the diamond.

    Optimum Shape is: Length to Width ratio 0.9-1.2:1, or which is most pleasing to the eye
  • Marquise

    Marquise

    Nothing speaks of femininity, elegance and timeless sophistication like the Marquise-cut diamond. The shape of a marquise diamond can maximize carat weight, giving a much larger-looking diamond. This brilliant-cut diamond looks beautiful set with round or pear-shaped side stones, and the length of the marquise makes fingers appear long and slender. The length-to-width ratio will determine the diamond's outline, or what it will look like when viewed from the top.

    Optimum Shape is: Length to Width ratio 2:1
    Acceptable are: Length to Width ratio 1.75-2.25:1
  • Emerald Cut

    Emerald Cut

    The Emerald cut uses a series of flat rectangular facets stepping down off the table to give it a unique brilliance, quite different to that of a round or curved shaped cut. Due to its larger, open table, this shape highlights the clarity of a diamond. If you choose an emerald-cut with a lower clarity grade, such as SI, be sure to review the clarity plot on the diamond certificate.

    Optimum Shape is: Length to Width ratio 1.35-1.65:1
    Acceptable are: Length to Width ratio 1.25-1.75:1
  • Trilliant Cut

    Trilliant Cut

    One of the more unusual cuts the trilliant displays a very sharp brilliance or fire if the diamond is cut to the correct depth allowing good scintillation. Excellent for shoulder diamonds accompany a square or rectangular shaped diamond.

    Optimum Shape: Length to Width ratio 1:1
    Acceptable are: Length to Width ratio 1:1
  • Pear Cut

    Pear Cut

    This pear-shaped brilliant-cut diamond is also called a teardrop for its single point and rounded end. The unique look of the pear shape helps making it to be a popular choice for a variety of diamond jewelry. The pear shape uses the base of a brilliant or round cut, if well proportioned, it gives a depth of scintillation to the point of the stone. This cut of stone elongates the bearer’s fingers and enables them looks like slimmer, making it delicate and light. As far as luminosity, it is comparable to the most faceted of the lot, with unparalleled sparkle and falls into the brilliant cut category.

    Optimum Shape: Length to Width ratio 1.5:1
    Acceptable are: Length to Width ratio 1.5-1.7:1
  • Radiant Cut

    Radiant Cut

    Trimmed corners are the signature of this diamond, and they help make the radiant-cut a popular and elegant choice for jewelry. The Radiant can either be cut as a square or rectangle. An essentially square-to-rectangular shaped diamond, this cut boasts facets best appreciated from bird’s eye view. The Radiant has a strong look with a unique type sparkle, differing from Emerald and Princess Cuts. Radiant-cut diamonds can vary in their degree of rectangularity.

    Optimum Shape; For Square Length to Width ratio 1:1
    Acceptable are; For Rectangle Length to Width ratio 1.5:1
  • Curved Trilliant Cut

    Curved Trilliant Cut

    A softer look than the straight edge trilliant , a more unusual cut for a diamond , a bold fattish looking shape, deep and strong appearance , three soft points, three lines of curvature , nice if well proportioned.

    Optimum Shape: Length to Width ratio 1:1
    Acceptable are: Length to Width ratio 1.1 to 1
  • Baguette Cut

    Baguette Cut

    Coming from the French bread stick. The Baguette may be cut long or more emerald shaped in proportions. As a main stone, the proportions should be more like a rectangle shape. The Baguette is for those people who want a long stone, usually used are small baguettes to accompany different shaped diamonds.

    Optimum Shape: Length to Width ratio 1.5:1
    Acceptable are: Length to Width ratio 1.5.-2.5:1
  • Asscher Cut

    Asscher Cut

    This beautifully unique shape is nearly identical to the emerald-cut, except that it is square. Also, this shape has a pavilion that is cut with rectangular facets in the same style as the emerald-cut. Due to sharp and plentiful surface area, one should choose with refinement a higher clarity grade of diamond as this cut displays brilliance with the same vigor that it would display any color, especially around the edges. Joseph Asscher was an eminent diamond cutter who cut the 3,106 carat Cullinan diamond. Asscher worked in Amsterdam. In 1902, his company, the Asscher Diamond Co., developed and patented the Asscher cut, a squarish step cut with an almost octagonal outline.
    Optimum Shape: Length to Width ratio 1:1
    Acceptable are: Length to Width ratio 1-1.4:1
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