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Jewelry Education - The 4 C's
Cut
Round |
The round brilliant diamond is the most popular diamond shape, the most brilliant of all the cuts, and is the most expensive.
Round diamonds are most often found in engagement rings and are popular as stud earrings and in pendants. |

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Princess |
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Most people like the Princess because it is rectangular and yet has some of the sparkle of a Round brilliant cut.
The princess cut may have either 50 facets (21 crown, 4 girdle, 25 pavilion) or 58 facets (21 crown, 4 girdle, 33 pavilion), depending on how the pavilion is cut. This cut is most frequently a square shape where the length to width ratio is 1.0 to 1.1.
The princess cut tends to be the smallest of the shapes for the same carat weight since the cut is basically an upside-down pyramid with most of the carat weight in the pavilion. Princess cut requires great care when setting and needs to be protected to avoid chipping or cracking. |
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Oval |
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Ovals provide a bigger surface area than a round with the same carat weight and therefore are an excellent option for shoppers looking for a brilliance of the round but a bigger size for their dollar.
Usually oval cut has the standard 58 facet pattern. Look for even, well rounded ends with a full body having an optimal length-to-width ratio of 1.33-1.66. |
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Emerald |
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The emerald cut is not a brilliant cut, but is called a step cut. Step cuts are comprised of larger facets which act like mirrors. Because of the angle, size and shape of the facets, the emerald cut shows less brilliance than the other brilliant cut diamonds.
However, the emerald cut stone reveals a classic beauty and elegance not seen in other cuts. Because of the open and large facets, we recommend a higher colour and clarity than you might consider for a brilliant cut stone because they are more likely to become visible at lower grades. |
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Pear |
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The Pear Shaped Brilliant is a combination of a Round brilliant and a Marquise cut.
The pear shape usually has the 58 facet brilliant pattern, but can be cut with different numbers of pavilion mains of 8,7,6, or 4 facets. In a pear, look for a well-shaped point and an even shaped opposite end with a length-to-width ratio of 1.50-1.75.
Pear-shaped diamonds work great for pendants and drop earrings. |
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Heart |
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The heart shape is a brilliant cut and bears some similarity to the pear shape, except that there is a cleft at the top.
It is important to look for a perfectly symmetrical appearance where the lobes (top arches) are of even height and breadth, and the overall shape is pleasing to the eye. |
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Marquise |
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The name "Marquise" came from a legend of the Marquise of Pompadour that the Sun King wanted a Diamond to be polished into the shape of the mouth of the Marquise!
The marquise is typically cut into 58 facet standard brilliant (33 crown, 25 pavilion), the same as the round brilliant. The crown cut is sometimes modified in the marquise to form what is called a "French Tip," where the bezel facet at the point of the stone is eliminated. Marquise diamonds frequently display a bow tie, so try to find a stone in which this is minimal or absent. The marquise has a very big surface area for the carat weight so it's an excellent option if you want a big, long look for less dollars. |
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Trillion |
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The trillion cut was developed in the late seventies.
The trillion is a triangle that has equilateral sides. It is a combination cut of the step and the brilliant cut diamond and when cut correctly has a wonderful brilliance. It is often cut shallow and often looks large for its carat weight.
Trillion diamonds are beautiful when flanking a centre diamond, or in a more avant-garde piece as a centre diamond. A matched pair also creates beautiful earrings. |
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Baguette |
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The baguette is a step cut style used frequently as a side stone.
Baguettes have unbevelled corners, usually only two rows of facets, and may be rectangular or tapered. Like the emerald cut, the baguette does not have the sparkle of a brilliant cut but has a classic beauty. |
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The finished diamond should be symmetrical. The table should be symmetrical, well-cantered, and flat, not sloping. The cutlet should be cantered when viewed from the top. The crown and pavilion facets should be in exact geometric relation to one another. And, the girdle should be perfectly round exhibiting a straight edge when viewed from the side. |

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Too Shallow - Diamonds that are cut too thin or shallow allow the light to pass through the sides of the diamond and appear lifeless, dull, or flat in the center. |

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Too Deep - Diamonds that are cut too deep or high do not reflect enough light back through the top of the diamond and appear to be dark in the center. |
Clarity
Clarity measures the relative visibility of external blemishes or internal imperfections (inclusions) naturally occurring within a diamond as evaluated by a qualified gemologist. The clarity scale, established by the GIA (Gemological Institute of America), is divided into six primary categories.

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(F or FL) Flawless
No discernible surface blemishes or inclusions visible when viewed at 10x magnification.
(IF) Nearly Flawless
Insignificant surface blemishes and no internal defects visible at 10x magnification. |

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(VVS-1 & VVS-2) Very, Very Slight Inclusions
Extremely difficult to very difficult to find surface blemishes or minute inclusions at 10x magnification, but can be more readily seen at 10x once located at 20x magnification. |

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(VS-1 & VS-2) Very Slight Inclusions
Difficult to somewhat easy to find surface blemishes or minor inclusions at 10x magnification.
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(SI-1 & SI-2) Slight Inclusions
Easy to very easy to find surface blemishes or readily noticeable inclusions at 10x magnification, but will usually appear to be "eye clean" without magnification, though some stones will show slight inclusions when viewed from the side against a white background (note: GIA does not recognize an SI-3 clarity grade). |

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(I-1) Imperfect
Surface blemishes or obvious inclusions are somewhat difficult to find with the naked eye, but are easy to see especially after being located with 10x. |

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(I-2, I-3) Imperfect
Surface blemishes or obvious inclusions are somewhat easy, or very easy to find with the naked eye. I-2 inclusions will have an effect on either the diamond's aesthetic appearance (beauty) or durability (potential for cracking), I-3 inclusions will have an effect on both. |
Carat
The weight of a diamond is generally given in carats. One carat equals 0.2 grams. The weight of small diamonds is frequently expressed in points, with one point equalling 0.01 carats.
As diamonds increase in weight, their size becomes less predictable. Diamonds with a shallow cut can have a greater diameter than a deep cut with the same weight. So if size is important to you, focus on diamond measurements as opposed to carat weight. Diamonds that look big for their weight may have reduced brilliance and fire. An increase in carat weight does not produce the same increase in millimetre diameter. For example, there is a 25% increase in carat weight from 1.00 carats to 1.25 carats but less than 8% increase in diameter (6.5 to 7.0 mm).
Look for diamonds that have a diameter measurement that is at least as large as the average for that carat weight. There is no need to pay for the carat weight you can't see.

Colour

The colour scale is used to evaluate a diamond's internal tint, as well as playing a significant role in determining its price, colourless diamonds being the most desirable of course. Colour is best evaluated in natural light, as high intensity artificial lighting can make the diamond appear to be of a better colour grade than it actually is. Diamonds should also be examined for fluorescence, as blue photoluminescence will also make the diamond appear to be of a better colour grade.
Colour Grades
- (D-F) Colourless - tint nearly undetectable to unaided, trained eye even when compared to white standard.
- (G-H) Near Colourless - tint almost undetectable to the trained eye, but apparent when compared to white standard.
- (I-J) Near Colourless - trace of tint just detectable to the trained eye, but noticeably apparent when compared to white standard.
- (K-M) Faint Yellow to Faint Brown - tint apparent to the trained eye and readily apparent when compared to white standard.
- (N-R) Very Light Yellow to Very Light Brown - tint is easily apparent to the unaided, trained eye.
- (S-Z) Light Yellow to Light Brown - tint is obvious to the unaided, trained eye.
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