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)Before you start diamond shopping, you NEED to have an understanding of what you’re buying. This complete JREIS guide to Diamonds and the four Cs of diamonds — cut, color, clarity, and carat weight, so you can select your diamond based on the same criteria jewelers use to grade them.
After reading through this guide, you’ll be ready to choose the diamond that’s right for you. Be sure to look out for future JREIS Guides to Diamonds, Lab Created, Moissanite, Simulated, Clarity Enhanced gem stones, Certified stones, Stone pricing and more.
Hello, my name is J. Reis I have been buying and selling precious stones for many years and have a background in GIA training and grading. I will be writing several guides to help you buy diamonds at prices like a direct wholesale distributor, or at least save you some money. Even if you don’t buy any diamonds in the near future my guides will educate you on how to pick out the right stone for you when you are ready.
4 C’s of Diamonds - Cut, Color, Clarity, Carat Weight
CUT
The cut of a diamond has the most effect on its sparkle, or brilliance. Even if the diamond has perfect color and clarity, a poor cut can make it sparkle and have less fire than an I3 commercial grade diamond with a excellent cut.
For a diamond with the best cut, that will look exceptional even when viewed under a microscope you want a good cut or better. These diamonds reflect the most brilliance because they are cut to the most exacting proportions and have either excellent or very good polish and symmetry grades.
The width and depth can have an effect on how light travels within the diamond, and how it exits in the form of brilliance.
Too Shallow: Light is lost out the bottom causing the diamond to lose brilliance.
Too Deep: Light escapes out the sides causing the diamond to appear dark and dull.
For the best value in a brilliant diamond, choose a diamond with a cut grade of good or very good, and polish and symmetry grades of very good or good.
If your diamond has an ideal- or very-good cut with very good or good polish and symmetry, you may want to consider less expensive grades of color and clarity — look for a diamond with G or H color and SI1 or SI2 clarity. Instead of a diamond with D or E color and VVS or VS clarity and has lower grade cut or polish and symmetry.
Ideal cut: Represents roughly the top 3% of diamond quality based on cut. Reflects nearly all light that enters the diamond. An exquisite and rare cut.
Very good cut: Represents roughly the top 15% of diamond quality based on cut. Reflects nearly as much light as the ideal cut, but for a lower price.
Good cut: Represents roughly the top 25% of diamond quality based on cut. Reflects most light that enters. Much less expensive than a very good cut.
Fair cut: Represents roughly the top 35% of diamond quality based on cut. Still a quality diamond, but a fair cut will not be as brilliant as a good cut.
Poor cut: This includes all diamonds that do not meet the performance standards of a fair cut. These diamonds are generally deep and narrow or shallow and wide and tend to lose most of the light out the sides and bottom. Blue Nile does not carry diamonds with cut grades of poor.
Determining a diamond’s cut grade, however, goes beyond simple measurements of width and depth. Using an optical measuring device, a three-dimensional model is created to determine the diamond’s proportions and angles. The interrelations between these various dimensions will greatly affect how light reacts once it enters and how it behaves once it exits; by using sophisticated computer modeling, it is possible to trace light behavior and measure its levels of brightness, fire, and brilliance - the face-up appearance.
Diameter: The width of the diamond as measured through the girdle.
Table: The largest facet of a gemstone.
Crown: The top portion of a diamond extending from the girdle to the table.
Girdle: The intersection of the crown and pavilion which defines the perimeter of the diamond.
Pavilion: The bottom portion of a diamond, extending from the girdle to the culet.
Culet: The facet at the tip of a gemstone. The preferred culet is not visible with the unaided eye (graded “none” or “small”).
Depth: The height of a gemstone measured from the culet to the table.
COLOR
Acting as a prism, a diamond can divide light into a spectrum of colors and reflect this light as colorful flashes called fire. Just as when looking through colored glass, color in a diamond will act as a filter, and will diminish the spectrum of color emitted. The less color in a diamond, the more colorful the fire, and the better the color grade.
Diamonds are graded on a color scale of D-Z. D on the scale is best being colorless and Z being worst having yellow-brownish color
The color in diamonds graded K-Z detracts from the beauty of a diamond. It’s especially noticeable set in platinum or white gold.
D Absolutely colorless. The highest color grade, which is extremely rare. E Colorless. Only minute traces of color can be detected by an expert gemologist. A rare diamond. F Colorless. Slight color detected by an expert gemologist, but still considered a “colorless” grade. A high-quality diamond. G-H Near-colorless. Color noticeable when compared to diamonds of better grades, but these grades offer excellent value. I-J Near-colorless. Color slightly detectable. An excellent value. K-M Noticeable color. N-Z Noticeable color.
Some people seek diamonds that produce this unique effect, while others definitely avoid it. The visible effects of fluorescence grades of faint, inert, negligible, and medium, can only be detected by a trained gemologist. A fluorescence grade of strong or very strong can make a diamond with a near-colorless grade look even whiter yet in some instances give the diamond a slight hazy or oily appearance. Diamonds with a strong or very strong fluorescence are priced slightly lower than other diamonds.
For the purist, look for a colorless diamond with a grade of D-F and a fluorescence rating of faint, inert, none, or negligible.
For an excellent value in a diamond with no noticeable color to the unaided eye, look for a near-colorless grade of G-I, and a fluorescence grade of medium or strong blue.
Or, if you’d rather not compromise on color but would like to stay on budget, choose a diamond with a good cut, SI1–SI2 clarity, and consider going with a strong fluorescence. It will still be beautiful to the unaided eye and you may prefer the unique effect of a strong fluorescence.
CARAT WEIGHT
Once you’ve determined what cut, color, and clarity grade you’re looking for in a diamond, it’s easy to determine the carat weight of diamond that will fit within your budget.
1ct = 100 POINTS
When diamonds are mined, large gems are discovered much less frequently than small ones, which makes large diamonds much more valuable. In fact, diamond prices rise exponentially with carat weight. So, a 2-carat diamond of a given quality is always worth more than two 1-carat diamonds of the same quality.
To choose the best carat weight of diamond, consider her style, the size of her finger, the size of your setting, and your budget.
If you have a set budget, explore all your options and you’ll find that there is a wide range of diamond carat weights and qualities available in your price range.
If your recipient is very active or not used to wearing jewelry, she may find herself bumping or nicking her new ring. Consider a smaller size diamond or a setting that protects a larger diamond from getting knocked against doors and counters.
Also keep in mind that the smaller the finger, the larger the diamond will appear. A 1½-carat diamond solitaire looks much larger on a size 4 finger than a size 8.
If you have already chosen a setting, make sure you choose a diamond to fit. Look for the diamond size specifications of your ring or ask your jeweler what size diamond you should look for.
Finally, if a large carat weight is important to you, yet you’re working within a budget, consider a diamond with a good cut, SI1–SI2 clarity, and an I or J color grade.
CLARITY
Diamonds that are absolutely clear are the most sought-after and therefore the most expensive. But many diamonds have inclusions — scratches, trace minerals or other tiny characteristics that can detract from the pure beauty of the diamond. The GIA and AGSL use a detailed system of rules and standards to summarize the number, location, size, and type of inclusions present in a diamond.
FL, IF Flawless, Internally Flawless: No internal or external flaws. Internally Flawless: No internal flaws. Very rare and beautiful diamonds. VVS1,
VVS2 Very, Very Slightly Included: Very difficult to see inclusions under 10x magnification. An excellent quality diamond. VS1,
VS2 Very Slightly Included: Inclusions are not typically visible to the unaided eye. Less expensive than the VVS1 or VVS2 grades. SI1,
SI2 Slightly Included: Inclusions are visible under 10x magnification, and may be visible with the unaided eye. A good diamond value. I1, I2, I3 Included: Commercial diamonds usually what you see at Zales and other mall retailers.
DIAMOND SHAPES
Since all diamond shapes are very different, unique characteristics determine quality for each shape. Select your shape below to learn how to recognize the most beautiful diamond.
ROUND
The round brilliant cut diamond is by far the most popular and most researched diamond shape available today. 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. In addition to being the most popular and researched shape, a round diamond will typically give you more flexibility in terms of balancing cut, color, and clarity grades while still getting the fire and brilliance you want.
To maximize the brilliance of a traditional round diamond, select one in the two highest cut grades, ideal or very good, and choose ideal, excellent, or very good polish and symmetry grades.
PRINCESS
The princess has pointed corners and is traditionally square in shape. When choosing a color grade, consider that while the price of a J-color non-round diamond is exceptional, color may be slightly visible in its corners. Also, princess-cut diamonds can vary greatly in how square or rectangular they are.
EMERALD
What makes this shape different is its pavilion, which is cut with rectangular facets to create a unique optical appearance. 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. Also, emerald-cut diamonds can vary greatly in how rectangular they are. If you’d prefer an emerald cut with a squared outline, look for an Asscher-cut diamond.
ASSCHER
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. If you choose SI-clarity be sure to view the clarity plot on the diamond certificate, because this shape highlights the clarity of the diamond. When choosing a color grade, consider that while the price of a J-color non-round diamond is exceptional, color may be slightly visible in its corners.
OVAL
An oval diamond has beautiful brilliance that’s similar to a round diamond. Oval diamonds are also very popular as their length can accentuate long, slender fingers.
MARQUISE
The shape of a marquise diamond can maximize carat weight, giving you 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.
PEAR
This brilliant-cut diamond is also called a teardrop for its single point and rounded end. The unique look of the pear shape helps make it a popular choice for a variety of diamond jewelry.
RADIANT
Trimmed corners are the signature of this diamond, and they help make the radiant-cut a popular and versatile choice for jewelry. A radiant-cut looks equally beautiful set with either baguette or round side-diamonds. Radiant-cut diamonds can vary in their degree of rectangularly.
CUSHION
This unique shape has been popular for more than a century. Cushion-cut diamonds (also known as “pillow-cut” diamonds) have rounded corners and larger facets to increase their brilliance. These larger facets highlight the diamond’s clarity, so if you choose an SI clarity grade, be sure to review the clarity plot on the diamond certificate. Cushion-cut diamonds are available in shapes ranging from square to rectangular.
HEART
The heart is the ultimate symbol of love. The unique look of the heart-shaped diamond helps make it a distinctive choice for a variety of diamond jewelry. When choosing a color grade, consider that while the price of a J-color heart shaped diamond is exceptional, color may be slightly visible in its corners.
After reading through this guide, you’ll be ready to choose the diamond that’s right for you. Be sure to look out for future JREIS Guides to Diamonds, Lab Created, Moissanite, Simulated, Clarity Enhanced gem stones, Certified stones, Stone pricing and more.
Hello, my name is J. Reis I have been buying and selling precious stones for many years and have a background in GIA training and grading. I will be writing several guides to help you buy diamonds at prices like a direct wholesale distributor, or at least save you some money. Even if you don’t buy any diamonds in the near future my guides will educate you on how to pick out the right stone for you when you are ready.
4 C’s of Diamonds - Cut, Color, Clarity, Carat Weight
CUT
The cut of a diamond has the most effect on its sparkle, or brilliance. Even if the diamond has perfect color and clarity, a poor cut can make it sparkle and have less fire than an I3 commercial grade diamond with a excellent cut.
For a diamond with the best cut, that will look exceptional even when viewed under a microscope you want a good cut or better. These diamonds reflect the most brilliance because they are cut to the most exacting proportions and have either excellent or very good polish and symmetry grades.
The width and depth can have an effect on how light travels within the diamond, and how it exits in the form of brilliance.
Too Shallow: Light is lost out the bottom causing the diamond to lose brilliance.
Too Deep: Light escapes out the sides causing the diamond to appear dark and dull.
For the best value in a brilliant diamond, choose a diamond with a cut grade of good or very good, and polish and symmetry grades of very good or good.
If your diamond has an ideal- or very-good cut with very good or good polish and symmetry, you may want to consider less expensive grades of color and clarity — look for a diamond with G or H color and SI1 or SI2 clarity. Instead of a diamond with D or E color and VVS or VS clarity and has lower grade cut or polish and symmetry.
Ideal cut: Represents roughly the top 3% of diamond quality based on cut. Reflects nearly all light that enters the diamond. An exquisite and rare cut.
Very good cut: Represents roughly the top 15% of diamond quality based on cut. Reflects nearly as much light as the ideal cut, but for a lower price.
Good cut: Represents roughly the top 25% of diamond quality based on cut. Reflects most light that enters. Much less expensive than a very good cut.
Fair cut: Represents roughly the top 35% of diamond quality based on cut. Still a quality diamond, but a fair cut will not be as brilliant as a good cut.
Poor cut: This includes all diamonds that do not meet the performance standards of a fair cut. These diamonds are generally deep and narrow or shallow and wide and tend to lose most of the light out the sides and bottom. Blue Nile does not carry diamonds with cut grades of poor.
Determining a diamond’s cut grade, however, goes beyond simple measurements of width and depth. Using an optical measuring device, a three-dimensional model is created to determine the diamond’s proportions and angles. The interrelations between these various dimensions will greatly affect how light reacts once it enters and how it behaves once it exits; by using sophisticated computer modeling, it is possible to trace light behavior and measure its levels of brightness, fire, and brilliance - the face-up appearance.
Diameter: The width of the diamond as measured through the girdle.
Table: The largest facet of a gemstone.
Crown: The top portion of a diamond extending from the girdle to the table.
Girdle: The intersection of the crown and pavilion which defines the perimeter of the diamond.
Pavilion: The bottom portion of a diamond, extending from the girdle to the culet.
Culet: The facet at the tip of a gemstone. The preferred culet is not visible with the unaided eye (graded “none” or “small”).
Depth: The height of a gemstone measured from the culet to the table.
COLOR
Acting as a prism, a diamond can divide light into a spectrum of colors and reflect this light as colorful flashes called fire. Just as when looking through colored glass, color in a diamond will act as a filter, and will diminish the spectrum of color emitted. The less color in a diamond, the more colorful the fire, and the better the color grade.
Diamonds are graded on a color scale of D-Z. D on the scale is best being colorless and Z being worst having yellow-brownish color
The color in diamonds graded K-Z detracts from the beauty of a diamond. It’s especially noticeable set in platinum or white gold.
D Absolutely colorless. The highest color grade, which is extremely rare. E Colorless. Only minute traces of color can be detected by an expert gemologist. A rare diamond. F Colorless. Slight color detected by an expert gemologist, but still considered a “colorless” grade. A high-quality diamond. G-H Near-colorless. Color noticeable when compared to diamonds of better grades, but these grades offer excellent value. I-J Near-colorless. Color slightly detectable. An excellent value. K-M Noticeable color. N-Z Noticeable color.
Some people seek diamonds that produce this unique effect, while others definitely avoid it. The visible effects of fluorescence grades of faint, inert, negligible, and medium, can only be detected by a trained gemologist. A fluorescence grade of strong or very strong can make a diamond with a near-colorless grade look even whiter yet in some instances give the diamond a slight hazy or oily appearance. Diamonds with a strong or very strong fluorescence are priced slightly lower than other diamonds.
For the purist, look for a colorless diamond with a grade of D-F and a fluorescence rating of faint, inert, none, or negligible.
For an excellent value in a diamond with no noticeable color to the unaided eye, look for a near-colorless grade of G-I, and a fluorescence grade of medium or strong blue.
Or, if you’d rather not compromise on color but would like to stay on budget, choose a diamond with a good cut, SI1–SI2 clarity, and consider going with a strong fluorescence. It will still be beautiful to the unaided eye and you may prefer the unique effect of a strong fluorescence.
CARAT WEIGHT
Once you’ve determined what cut, color, and clarity grade you’re looking for in a diamond, it’s easy to determine the carat weight of diamond that will fit within your budget.
1ct = 100 POINTS
When diamonds are mined, large gems are discovered much less frequently than small ones, which makes large diamonds much more valuable. In fact, diamond prices rise exponentially with carat weight. So, a 2-carat diamond of a given quality is always worth more than two 1-carat diamonds of the same quality.
To choose the best carat weight of diamond, consider her style, the size of her finger, the size of your setting, and your budget.
If you have a set budget, explore all your options and you’ll find that there is a wide range of diamond carat weights and qualities available in your price range.
If your recipient is very active or not used to wearing jewelry, she may find herself bumping or nicking her new ring. Consider a smaller size diamond or a setting that protects a larger diamond from getting knocked against doors and counters.
Also keep in mind that the smaller the finger, the larger the diamond will appear. A 1½-carat diamond solitaire looks much larger on a size 4 finger than a size 8.
If you have already chosen a setting, make sure you choose a diamond to fit. Look for the diamond size specifications of your ring or ask your jeweler what size diamond you should look for.
Finally, if a large carat weight is important to you, yet you’re working within a budget, consider a diamond with a good cut, SI1–SI2 clarity, and an I or J color grade.
CLARITY
Diamonds that are absolutely clear are the most sought-after and therefore the most expensive. But many diamonds have inclusions — scratches, trace minerals or other tiny characteristics that can detract from the pure beauty of the diamond. The GIA and AGSL use a detailed system of rules and standards to summarize the number, location, size, and type of inclusions present in a diamond.
FL, IF Flawless, Internally Flawless: No internal or external flaws. Internally Flawless: No internal flaws. Very rare and beautiful diamonds. VVS1,
VVS2 Very, Very Slightly Included: Very difficult to see inclusions under 10x magnification. An excellent quality diamond. VS1,
VS2 Very Slightly Included: Inclusions are not typically visible to the unaided eye. Less expensive than the VVS1 or VVS2 grades. SI1,
SI2 Slightly Included: Inclusions are visible under 10x magnification, and may be visible with the unaided eye. A good diamond value. I1, I2, I3 Included: Commercial diamonds usually what you see at Zales and other mall retailers.
DIAMOND SHAPES
Since all diamond shapes are very different, unique characteristics determine quality for each shape. Select your shape below to learn how to recognize the most beautiful diamond.
ROUND
The round brilliant cut diamond is by far the most popular and most researched diamond shape available today. 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. In addition to being the most popular and researched shape, a round diamond will typically give you more flexibility in terms of balancing cut, color, and clarity grades while still getting the fire and brilliance you want.
To maximize the brilliance of a traditional round diamond, select one in the two highest cut grades, ideal or very good, and choose ideal, excellent, or very good polish and symmetry grades.
PRINCESS
The princess has pointed corners and is traditionally square in shape. When choosing a color grade, consider that while the price of a J-color non-round diamond is exceptional, color may be slightly visible in its corners. Also, princess-cut diamonds can vary greatly in how square or rectangular they are.
EMERALD
What makes this shape different is its pavilion, which is cut with rectangular facets to create a unique optical appearance. 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. Also, emerald-cut diamonds can vary greatly in how rectangular they are. If you’d prefer an emerald cut with a squared outline, look for an Asscher-cut diamond.
ASSCHER
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. If you choose SI-clarity be sure to view the clarity plot on the diamond certificate, because this shape highlights the clarity of the diamond. When choosing a color grade, consider that while the price of a J-color non-round diamond is exceptional, color may be slightly visible in its corners.
OVAL
An oval diamond has beautiful brilliance that’s similar to a round diamond. Oval diamonds are also very popular as their length can accentuate long, slender fingers.
MARQUISE
The shape of a marquise diamond can maximize carat weight, giving you 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.
PEAR
This brilliant-cut diamond is also called a teardrop for its single point and rounded end. The unique look of the pear shape helps make it a popular choice for a variety of diamond jewelry.
RADIANT
Trimmed corners are the signature of this diamond, and they help make the radiant-cut a popular and versatile choice for jewelry. A radiant-cut looks equally beautiful set with either baguette or round side-diamonds. Radiant-cut diamonds can vary in their degree of rectangularly.
CUSHION
This unique shape has been popular for more than a century. Cushion-cut diamonds (also known as “pillow-cut” diamonds) have rounded corners and larger facets to increase their brilliance. These larger facets highlight the diamond’s clarity, so if you choose an SI clarity grade, be sure to review the clarity plot on the diamond certificate. Cushion-cut diamonds are available in shapes ranging from square to rectangular.
HEART
The heart is the ultimate symbol of love. The unique look of the heart-shaped diamond helps make it a distinctive choice for a variety of diamond jewelry. When choosing a color grade, consider that while the price of a J-color heart shaped diamond is exceptional, color may be slightly visible in its corners.
Guide created: 02/22/07 (updated 06/16/09)
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