THE FOUR Cs OF DIAMONDS

Value can differ greatly from one diamond to the next. This value is determined based on the 4Cs: cut, color, clarity, and carat weight. The 4Cs are a universally accepted standard to diamond grading and are the most important characteristics to consider when buying a diamond.

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Diamond Clarity

Most diamonds have distinct clarity characteristics. These characteristics behave much like a fingerprint and differ from one diamond to the next. These can be classified as inclusions and blemishes. Blemishes are confined to a diamond’s surface, while inclusions can be defined as small imperfections that are enclosed within the diamond, or that extend into the diamond from its surface. When light enters a diamond, that same flow of light is reflected inside the diamond and then refracted back out. If anything obstructs the flow of light through the diamond, such as a blemish, a portion of the light reflected is lost, decreasing the brilliance and pure beauty of the diamond.

 

To get the most value, The Engagement Ring Studio suggests selecting a diamond that is “eye clean” — a diamond in which no internal or external flaws are visible to the naked eye. The table here illustrates how a flaw (inclusion or blemish) may appear under 10x magnification.

 

When inspecting a diamond, you may not notice a significant difference between an SI1 and an SI2 with the unaided eye. As no two diamonds are the same and do not have the same flaws in the same exact locations, you should consider the size, brightness, nature, number and positions of the inclusions of an SI2 graded diamond to ensure that it is eye clean. Depending on these characteristics, some inclusions may be less noticeable or simply hidden by a prong when mounted, thus having little effect on the beauty of the diamond. However, an inclusion on the top or the middle of the diamond could effect the dispersion of light inside the diamond, making it less brilliant.

GIA Clarity Grading Scale

A diamond’s cut is considered to be the most important quality to consider when buying a diamond. It is also the most important of the four Cs. A diamond’s overall proportions, its width and depth, as well as the size and position of its facets, affects its brilliance, fire and scintillation. These qualities also have the greatest effect on how the flow of light travels within and exits the diamond.

FL – IF



Flawless and Internally Flawless

Flawless: No inclusions or blemishes
 of any sort under 10x magnification.
 Internally Flawless: No inclusions,
 but some minor blemishes.

SI1 – SI2

Slightly Included

Contains inclusions that are obvious under 10X magnification and possibly to the unaided eye.

VVS1 – VVS2

Very Very Slightly Included

Contains minute inclusions that are
very difficult to see under 10x magnification, 
even for an experienced grader.

I1 – I2 – I3



Included

Contains inclusions noticeable under 10x magnification. An SI1 should not have any eye visible inclusions, but SI2 may, depending on the size and location of the flaws.

VS1 – VS2

Very Slightly Included

Contains minute inclusions when observed with effort under
 10x magnification. An excellent value
as there is no noticeable difference
 to the unaided eye from VVS.

Diamond Color

Diamond color is another important factor to consider when buying a diamond, as color is easily seen by the unaided eye. The color of a diamond is graded on an alphabetical scale from D to Z by GIA, with D being colorless and Z being light yellow. Beyond Z is considered “fancy” color. Many diamonds have a hint of color, despite appearing to be colorless.

 

A diamond’s color also has a considerable impact on its value. The Engagement Ring Studio carries diamonds in the color range from D to J only to ensure the highest quality diamonds for your selection. When shopping for a diamond, keep in mind that for all diamonds mounted in jewelry, it is difficult to discern the difference between a colorless diamond (D to F) and a near colorless diamond (G to J). Diamonds graded from K to Z generally have a yellow tint that is noticeable by the unaided eye, while a well cut stone with a lower color grade will still look beautiful due to its superior ability to disperse light and create brilliance.

D – J

(AGS 0.0-3.0)

Color to Near Colorless

K – R

(AGS 3.5-7.0)

Faint to Very Light Yellow

S – Z

(AGS 7.5-10.0)

Light Yellow to Fancy

View Color Scale

Shallow Cut Diamonds

Light leaks out of the bottom, brilliance is lost and the diamond appears watery, glassy and dark. A diamond with these characteristics is referred to as a “fisheye”.

Deep Cut Diamonds

Light leaks out of the sides, brilliance is lost and the center of the diamond will appear to be dark. A diamond with these characteristics is referred to as a “nailhead”.

Diamond Cut

A diamond’s cut is the most important quality to consider when buying a diamond. It is also the most important of the four Cs. A diamond’s overall proportions, its width and depth, as well as the size and position of its facets, affects its brilliance, fire and scintillation. These qualities also have the greatest effect on how the flow of light travels within and exits the diamond in the form of brilliance.

 

If the diamond is cut too shallow as in the picture below, the light escapes out of the bottom of the diamond. If the cut is too deep, the light leaks out the side. In either case, the diamond is left looking dark, dull and lifeless due to poor light return.

 

A diamond’s cut is graded by numerous measurements. Its table percentage (a measurement of the diameter of the top facet of the stone vs. the stone’s average width) and its depth percentage (a measurement of the height vs. the width of the stone) are two important factors one must consider when determining the quality of a diamond’s cut. These percentages are detailed on the GIA or EGL Diamond Grading Report that accompanies every Engagement Ring Studio diamond.

 

Because table size (the diameter of the largest facet on the top of the stone) and the best depth for a diamond alone are not enough to accurately judge a diamond’s cut, diamond experts express conflicting opinions on the best table size and diamond depth. In addition, there are other factors, such as crown angle, culet size, girdle thickness, symmetry and polish, that all play an important role in judging a diamond’s cut quality.

A diamond’s cut is graded by several measurements. Its depth percentage (a measurement of the height vs. the width of the stone) and its table percentage (a measurement of the diameter of the top facet of the stone vs. the stone’s average width) are two key factors in determining the quality of a diamond’s cut. These percentages are detailed on the GIA or EGL Diamond Grading Report that accompanies every Engagement Ring Studio diamond.

Carat Weight

The weight of a diamond is measured in carats, a unit of measurement equivalent to 200 milligrams. Each carat is divided into 100 points. Thus, a half-carat can be referred to as a “50-pointer” or “50-points”. Due to the use of highly advanced measuring equipment, carat weight is the easiest of the 4 C’s for gemologists to determine.

 

Diamonds of equal carat weight may vary significantly in value depending on their cut, clarity and color. This is important to remember because when mounted, one diamond may appear larger than the other when they actually weigh the same. If size is important to you when buying your diamond, be sure to focus on diamond measurements as opposed to carat weight. Diamonds that appear big for their weight may have less brilliance and fire due to a poorer cut, so always strive for a great cut.