A carat is the standard unit of measurement used to weigh diamond and gemstones. One carat (1.00 ct) equals 200 milligrams, or 0.200 grams. You may also have heard jewelers talking about "points". In common jewelry parlance, when referring to a diamond weighing less than one carat, jewelers use points, just like pennies are used for prices lower than one dollar. A point equals 0.01 ct. So, for example, a 15 point diamond is the same as a 0.15 ct diamond.

As large diamonds are rare, they have a greater value per carat and the price of diamonds rises exponentially in relation to size. Accordingly, a one carat diamond with a certain color and clarity will be much more valuable than two separate half carat diamonds of the same quality. Due to higher demand, diamonds increase in value after they reach the half and full carat mark.

			CARAT WEIGHT Choose a Carat Weight 1/4 1 1/2 1/3 2 1/2 3 3/4 4 1 5

It is a common misconception that a half-carat diamond is half the size of a one-carat diamond. While a half-carat diamond is half the weight of a one-carat diamond, the size difference in Round stones is only 1.35mm. The average measurements for a half-carat diamond and a one-carat stone are 5.00mm and 6.35mm, respectively.

• The best carat weight for a diamond often depends on the desired style, the size of the ring finger, the size of your setting, and your budget.
• While the size of the diamond significantly affects its price, it does not guarantee beauty. Before you buy a diamond, it is best to first make a decision about preferred quality and then choose the size of diamond that you can afford in that quality range.
• Remember that diamonds appear larger on smaller fingers. A 1.50 ct diamond solitaire will look bigger on a size 4 finger compared to a size 8 finger.
• If you prefer a 1.00 ct diamond but are limited by your budget, consider a 0.90 ct one. Size difference between 0.90 ct and 1.00 ct diamonds is only very slight — even imperceptible to the untrained eye. A well-crafted 0.90 ct will comparatively have more sparkle, fire and brilliance than a 1 ct one for the same price or even less. This same argument also applies to other diamonds of comparative size ratios.

Diamonds generally increase in value as their color moves from pale yellow to an absence of color that promotes more reflection and dispersal of light. Even the slightest tinge of yellow or brown in a white diamond will decrease its value. White diamonds are graded on a scale that uses the letters of the alphabet to describe color ranging from D (colorless) to Z (light yellow or brown).

Colorless

Near Colorless

Noticeable Color

 

D - Colorless
Absolutely colorless. This is the highest color grade and these diamonds are extremely rare.

E - Colorless
Colorless. These are rare diamonds that contain only minute traces of color as detected by a gemologist.

F - Colorless
Colorless. Still considered colorless grade, these high-quality diamonds have only a slight color as detected by a gemologist.

G - Near Colorless
Near colorless. These diamonds offer an excellent value and their color is mostly noticeable when compared to diamonds with better grades.

H - Near Colorless
Near colorless. These diamonds offer an excellent value and their color is noticeable when compared to diamonds with better grades.

I - Near Colorless
Near colorless. Color slightly detectable. An excellent value.

J - Near Colorless
Near colorless. Color slightly detectable. An excellent value.

K-M - Noticeable Color
Yellowish tint. This color does not show with smaller diamonds when they are mounted, but diamonds of half carat or more will show noticeable color to the untrained eye.

N-R - Noticeable Color
These diamonds show noticeable yellowish tints to the untrained eye.

S-Z - Noticeable Color
Yellow. These diamonds show increasing yellow or brownish tints and they are very off-white in color.

 

A note about Fluorescence

Fluorescence is a property of some diamonds to emit visible light when expose to invisible ultraviolet radiation. Fluorescence is detected by gemologist using special long wave and short wave ultraviolet lamp, and can manifest itself in daylight and some artificial lighting giving the diamond a bluish or milky appearance.

Though fluorescence lowers the value of a diamond, it can make it appear whiter and closer to colorless. Blue fluorescent coloring can actually improve the color of a diamond by a grade or two while lowering its value. Fluorescence occurs in varying degrees of color from a common blue to a rare yellow. Fluorescence is graded from None to Very Strong.

• When it comes to diamonds, most people find it very difficult (if not impossible) to tell the difference from one color grade to another. Despite this, color has a significant impact on the price of diamonds. Though purists prefer diamonds in the D to F range, you can find tremendous value and a colorless look by selecting diamonds in the G to I range.
• If you are shopping on a budget or trying to maximize the size of your stone, consider J diamonds that combine affordability with near colorlessness.
• Medium or strong fluorescence actually counteracts the slight yellow body color of diamonds that are rated I color or lower. As a result, these diamonds appear to be more white or colorless than they actually are. This gives the budget-conscious buyer the opportunity to purchase a lower-color but whiter-looking diamond that offers an appearance that is comparable to a more expensive, higher color diamond.

A diamond's clarity rating is based on the presence and visibility of internal flaws (called inclusions) and external flaws (called blemishes). Inclusions are naturally occurring impurities that can become embedded in a diamond during its formation. Blemishes can occur during cutting, polishing and wearing.

Clarity improves when a diamond has fewer flaws. A clarity grade is assigned based on the overall appearance of a diamond under 10x magnification. There are five factors that determine how a major laboratory will assign a clarity grade to a specific diamond:

Diamond clarity is graded according to the following scale:

FL

IF

VVS1-VVS2

VS1-VS2

SI1-SI2-SI3

I1-I2-I3

 

Flawless
No inclusions or blemishes are visible under 10x magnification. These diamonds are very rare, beautiful and expensive.

Internally Flawless
No inclusions and only insignificant blemishes can be seen under 10x magnification. These diamonds are very rare, beautiful and expensive and their blemishes can normally be removed by minor polishing.

Very very slightly included
Inclusions and blemishes are very difficult to see under 10x magnification. These are excellent quality diamonds.

Very slightly included
Inclusions are not typically visible to the unaided eye. VS1-VS2 diamonds contain minor inclusions that range from difficult to somewhat easy to see under 10x magnification. Though less expensive than VVS1-2 stones, these are excellent quality diamonds.

Slightly included
Inclusions are easily visible under 10x magnification and may be visible with the unaided eye. These diamonds still offer a great value at a much less cost than those with higher clarity ratings.

Imperfect
Inclusions are visible to the unaided eye and in some cases affects the durability of the diamond.

 

• It is important to select a diamond that does not have any inclusions that affect overall beauty and durability. If you want to be certain that your diamond is "eye clean" (i.e. no inclusions are visible to the unaided eye), select a diamond that is graded VS2 or higher.
• There are great values to be had when shopping for SI quality diamonds. To be certain that a diamond is free of inclusions visible to the naked eye, we recommend that you have it reviewed by our expert staff before finalizing your order.
• It is always a good idea to balance the clarity grade of your diamond with its color. If you are interested in diamonds in the D-F color range, focus on clarity grades of VS2 or higher. For excellent value, look for G-I color range diamonds with SI clarity.

Referring to the pattern of angled facets on the surface of the diamond, the cut of a diamond determines its brilliance and fire. People often confuse a diamond's cut with its shape. Whereas shape refers to the physical form and contour of the diamond, the quality of its cut dictates overall proportion and how it reacts to light. A diamond's sparkling character and reflective brilliance increases in proportion to the fineness of its cut.

The cut of a diamond includes considerations like symmetry, depth, crown and pavilion angles, uniformity of facets, quality of polish and the overall skill of the cutter that sculpted the stone. Most gemologists consider cut to be the most important diamond characteristic. A poor cut will dull the brilliance of a diamond of perfect color and clarity.

Cutting a diamond to ideal proportions sometimes requires sacrificing up to half of the crystal's initial weight. Consequently, such diamonds are sold at a relatively higher per-carat price.

> Learn more about Cut Grade

Diamond			Brilliant cut: Brilliant-cut is a specific diamond cutting style developed to maximize a diamond's optical properties. A Brilliant-cut diamond can have several shapes: Round, Princess, Marquise, Radiant, Pear, Oval, Heart and Cushion. A Brilliant-cut diamond that is well-cut, highly polished and well-balanced in proportion will give you that stunning fire, brilliance and sparkle you're looking for.

	Diameter: The width of the diamond as measured through the girdle.
	Table: The largest polished facet located on the top of the diamond.
	Crown: The top part of a diamond extending from the table to the girdle.
	Girdle: The edge of the diamond where the crown and pavilion meet.
	Pavilion: The bottom part of a diamond that extends from the girdle down to the culet.
	Culet: The small or pointed facet at the very bottom of a diamond.
	Depth: The height of the diamond as measured from the table to the culet.

< Back to Cut

Grading Cut:

Cut is the most difficult characteristic of a diamond to grade because it is based on a combination of aspects. These include crown depth, crown angle, pavilion depth, pavilion angle, the symmetrical arrangement of facets, polish - and more. Since the perfect balance of each is difficult to determine, the variance in the proportions between an Ideal Cut and a Poor Cut can be difficult to discern. Accordingly, the industry developed Diamond Cut Grading Standards to help in determining the quality of a diamond's cut.

The cut grade only applies to Round diamonds because they were the focus of the initial research conducted by cut grading laboratories. Though grading laboratories are slowly introducing cut grades for the fancy shapes like the Princess, Emerald, Oval, Radiant, Cushion and others, fancy shape diamonds with a laboratory cut grading remain rare. Each diamond shape has its own set of cut parameters that produce the optimal light performance and beauty for that particular shape.

Light Enters

Light Returns

Description Cut Grade

		Excellent/Ideal Perfectly proportioned and offering the highest grade of polish and symmetry, these stones reflect virtually all light. These diamonds are the most brilliant, rare and finest money can buy.
		Very Good Usually cut to maximize the size of the diamond, a Very Good Cut stone falls a little short of the ideal diamond proportions. A Very Good Cut Diamond reflects most of the light that enters the stone to provide a high level of brilliance.
		Good When a cutter chooses to create the largest possible diamond from a rough crystal, the proportions of the stone are beyond the ideal range. Much of the light that enters the stone is reflected back to deliver a good sparkle. This type of cut grade is an ideal choice for shoppers who want to stay in budget without sacrificing quality or beauty.
		Fair and Poor These stones are cut to maximize carat weight over other considerations. A diamond in this grade will reflect only a small proportion of the light that enters into it.

Polish refers to the overall smoothness of a diamond's surface. Polish grades indicate how visible the polishing marks (blemishes that are not significant enough to affect the clarity grade of the diamond) are on the facets of the diamond.

Though polish marks are almost always invisible to the unaided eye, they have a slight effect on the diamond's overall brilliance. Examples of blemishes that might be considered polish marks include faint polishing lines and small surface nicks or scratches. These marks are caused by microscopic diamond crystals that are pulled across the facet of the diamond by the polishing wheel during the cutting process.

Diamond polish is graded according to the following scale:

GOOD POLISH RESULTS IN ENHANCING BRILLIANCE	POOR POLISH RESULTS IN REDUCED BRILLIANCE

• Consider choosing a diamond with a Good polish grade. While diamonds with higher polish grades are desirable, there are fewer of them. Accordingly, they are generally more expensive than Good rated diamonds despite the fact that they are not noticeably better when viewed with the unaided eye.
• Be careful when buying diamonds with polish grades of Fair or Poor. The quality of their polish may limit the brilliance of the diamond.

Symmetry refers to the appropriateness of the diamond's shape and facet arrangement. Brilliance is diminished as a result of symmetry flaws such as variation in shape, alignment and the placement of diamond's facets in relation to one another. Symmetry grades indicate how visible these symmetry flaws are in the diamond.

Major symmetry flaws are often seen in diamonds that are graded as Fair or Poor. These flaws can include severe misalignment of facets, a noticeably off-center table, a noticeably off-center culet, a noticeably 'wavy' girdle, or a table which is noticeably not parallel to the girdle.

Diamond symmetry is graded according to the following scale:

Symmetry
	Off-Center Table The placement of the table (the largest facet on a diamond) should be centered at the top of the stone and needs to be parallel to the girdle. If the table is off-center or not parallel with the girdle this can cause uneven crown angles from one side to the other. In this example we see the unbalanced appearance that occurs from an off-center table.
	Off-Center Culet To check if the culet is centered, look at the diamond in the face-up position. You'll see the lower girdle facets through the table. If the lines formed by them look like a perfect square, the culet is centered. If the cross bends one way or the other, the culet is not centered. In this example we see what an off-centered culet might look like.
	Table & Girdle Not Parallel Here we see another example of what occurs when the table is not parallel with the girdle. As you see, the crown angle is much more steep on one side versus the other. From the top view you may have noticed an off-center table.

• Consider choosing a diamond with a Good symmetry grade. While diamonds with higher symmetry grades are desirable, there are fewer of them. Accordingly, they are generally more expensive than Good rated diamonds despite the fact that they are not noticeably better when viewed with the unaided eye.
• Be careful when buying diamonds with symmetry grades of Fair or Poor, The quality of their symmetry may affect the brilliance of the diamond.

Diamond laboratories are objective third-parties that independently grade diamonds and produce diamond certificates.

Also known as a "diamond grading report", a diamond certificate is a document in which a gemologist describes the physical characteristics of diamonds and assigns them standardized grades for characteristics such as cut, color, clarity, polish, symmetry and others.

• As an independent assessment of a diamond's quality, a diamond certificate is an important tool that can help you to make a good purchasing decision.

The length-to-width ratio of a diamond indicates how square or rectangular the diamond is when viewed from the top. This ratio applies to all diamond shapes except Round diamonds. Since length-to-width ratio has a major impact on a diamond's beauty, gemologists consider it an important characteristic when evaluating a diamond's cut.

Princess

Marquise

Emerald

Radiant

Pear

Oval

Heart

Asscher

Cushion

Princess
If you prefer a square-shaped Princess diamond, choose a length-to-width ratio between 1 and 1.05. For a quality rectangular shaped Princess diamond, look for a length-to-width ratio greater than 1.10.

Marquise
Diamonds with a classic Marquise shape usually have a length-to-width ratio between 1.75 and 2.25.

Emerald
If you prefer an Emerald cut with a square outline, look for an Asscher-cut diamond. For a classical Emerald shape, look for a length-to-width ratio between 1.30 and 1.50.

Radiant
If you prefer a square shaped Radiant diamond, look for a length-to-width ratio between 1 and 1.05. If you prefer a rectangular shape, the length-to-width ratio should be greater than 1.10.

Pear
A classical Pear shaped diamond has a length-to-width ratio between 1.45 and 1.75.

Oval
Classical oval shape diamonds have a length-to-width ratio between 1.33 and 1.66.

Heart
A wider Heart shape will have a length-to-width ratio between 0.85 and 1.00. For a longer, tapered design, try a length-to-width ratio between 1.00 and 1.10.

Asscher
A classical Asscher shape has a length-to-width ratio close to 1.00. If you prefer an Asscher-cut style with a more rectangular outline, look for an Emerald-cut stone.

Cushion
Those seeking a square shaped Cushion diamond should look for length-to-width ratio between 1 and 1.05. For a rectangular shaped Cushion, try a length-to-width ratio between 1.10 and 1.20.