Shopping for loose diamonds? Familiarize yourself with how diamonds are cut, graded, and valued.
Shape
Diamonds are cut in a variety of standard shapes each with its own unique properties and characteristics. Please note that the appearance of diamond from the top and often its pricing is affected by its particular proportions. Each diamond's length-to-width ratio describes these proportions and is noted in the detail tab of our diamond search pages.
Round: Round brilliant-cut diamonds are the most popular shape on the market today. The cutting technique used to create this shape enhances light refraction. As a result, round brilliant-cut diamonds display the most fire and brilliance, and are the most flexible when trying to balance maximum brilliance with cut, color, and clarity. They are also the most valuable shape, per carat, since more of their original mass is sacrificed in the cutting process.
Princess: The second most popular shape, traditional princess-cut diamonds are square with pointed corners. Price and quality vary depending on their length-to-width ratio. Traditional square shapes (with a length-to-width-ratio of around 1.0) are the most valuable, while more rectangular variations (with a length-to-width-ratio of greater than 1.1) are less costly.
Emerald: Emerald-cut diamonds are rectangular in shape, and get their distinctive look from the facets cut into their pavilion. This shape highlights diamond clarity, which is easily viewed due to its large, open table. Traditional emerald-cut shapes have a length-to-width ratios of about 1.30 to 1.40.
Asscher: Asscher-cut diamonds have the same distinct facets cut into their pavilion as emerald-cut diamonds. The primary difference is that asscher-cut diamonds are square, with a length-to-width ratio of about 1.0. As with emerald-cut diamonds, clarity is very visible in this shape, due to its large open table.
Marquise: Marquise-cut diamonds can look much larger for their carat weight than other shapes, due to their slender proportions. Traditional marquise-cut diamonds have a length-to-width ratios of about 1.75 to 2.25.
Oval: Oval-cut diamonds not only accentuate finger length, but like round brilliant-cut diamonds, maximize brilliance and fire due to their cutting style.
Radiant: With their signature trimmed corners and versatile use, radiant-cut diamonds are becoming increasingly popular. This cut can come in a variety of proportions, described by a stones' length-to-width ratio -- around 1.0 for a square shape or greater than 1.1 for a more rectangular shape.
Pear: Pear-cut diamonds have a very traditional look with a rounded end and pointed tip. Their length creates a finger slimming look and their shape works across a variety of jewelry styles.
Heart: A universal symbol of love and compassion, the heart-cut can be used in a variety of jewelry styles.
Cushion: Cushion-cut diamonds have a unique shape that gives them a cushion or pillow-like look. Brilliance is increased through their rounded corners and large facets.
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Cut
Cut is considered the most important characteristic of a diamond and is the key factor determining a diamond's brilliance. A well cut diamond will reflect light into and back out of the stone, maximizing its sparkle and beauty.
A cut grade refers to the symmetry and proportions of the diamond and how that affects the interaction between the diamond and the light around it.
An ideal cut will reflect all light that enters the diamond back out, emitting the most sparkle. If a diamond cut is too shallow, the light will enter and then escape out of the bottom of the diamond. If the diamond cut is too deep, the light will enter the diamond and leak out the sides.
Cut Grades
Excellent: Reflects almost all light that enters the diamond, superior and rare.
Very Good: Combines precise proportions with considerable price points, best in overall value and beauty.
Good: Reflects most light that enters.
Fair: Not entirely brilliant, light reflection is scarce.
Poor: Poor proportions allow for little to no light reflection.
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Clarity
Clarity, also known as purity or quality, refers to the number and size of the small naturally occurring imperfections present in almost all diamonds. There are two main types of imperfections -- inclusions and blemishes. Inclusions generally have more impact on the diamonds beauty and value; blemishes are easier to remove.
Clarity Grades
Flawless (F): No inclusions or blemishes under any type of 10x magnification. May include inscriptions and non-visible extra facets.
Internally Flawless (IF): No inclusions when examined under 10x magnifications. May include minor blemishes.
Very, Very Slightly Included (VVS2, VVS1): Minor inclusions that are difficult to see under 10x magnification.
Very Slightly Included (VS2, VS1): Minor inclusions such as crystals, small clouds, and small feathers that can be seen with experienced examination under 10x magnification.
Slightly Included (SI2, SI1): Noticeable inclusions such as clouds, crystals, knots, feathers, and cavities, which are viewable in experienced examination under 10x magnification.
Included: (I1, I2, I3): Obvious inclusions such as large feathers and crystals that are clearly observable under 10x magnification. This grade can affect transparency, brilliance, and durability.
How do you know which clarity grade is right for you?
Only you can decide which diamond fits you and your budget. If you're looking for a cost-effective choice -- with beauty in mind -- Slightly Included diamonds are good choice. These diamonds have imperfections that are not visible to the naked eye, and are an excellent value.
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Carat Weight
Size, which is often one of the first things people consider when purchasing a diamond, is measured in carat weight.
Since larger diamonds are increasingly rare, carat weight drastically affects price and rarity. Prices jump at half sizes, such as from a 0.50 to a 1.00 carat diamond.
How do you know which carat weight is right for you?
Start by understanding the basic characteristics of diamond shape, clarity, cut, and color and how they affect value. Then pick a carat weight that fits your budget. Remember, hand size and diamond shape affect how diamond size is perceived.
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Color
The color of a diamond actually refers to the lack of color, or whiteness of a diamond. The best color a diamond can have is no color, or a 'colorless' attribute. Most diamonds are nearly colorless with tints of brown and yellow from elements present during their formation.
Slight differences in color can cause dramatic differences in value. In the normal color range, the more colorless a diamond is, the higher its per-carat price.
Color Ranges
D (Absolutely colorless): The highest grade and most rare of all diamond color grades.
E - F (Colorless): A range of rare diamonds, with only nearly undetectable trace elements and tints viewable by expert examination.
G - H (Near-colorless): A excellent value. Color is hard to detect unless compared against stones with higher color grades.
I - J (Near-colorless): A great value, but do have some noticeable color.
K - Z (Noticeable color): Starting to head more towards fancy colored stone range.
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Certification
A diamond grading report or certificate is a document prepared by a gemological laboratory. It verifies a diamonds characteristics and quality for the non-expert consumer. The loose diamonds available online through our diamond search are graded by two internationally regarded laboratories:
The Gemological Institute of America (GIA)
Established in 1931, the Gemological Institute of America is the world's foremost authority on diamonds, colored stones, and pearls. GIA exists to protect all purchasers of gemstones, by providing the education, laboratory services, research, and instruments needed to accurately and objectively determine gemstone quality.
GIA Diamond Grading Report: The standard GIA Diamond Grading Report includes the following:
- assessment of a diamond's 4 C's = color, clarity, cut, and carat weight
- plotted diagram of clarity characteristics
- transparent sleeve packaging, lamination and other security features
- graphic representation of proportions
- for standard RBC diamonds in D-Z color range, report includes GIA cut grade
GIA laboratory issues diamond grading reports for loose, fully natural diamonds in D-Z color range, weighing 0.15 carats or more. Grading reports are NOT issued for synthetics, stimulants, mounted diamonds. or diamonds that have been subjected to unstable treatments. Stable treatments are noted on the GIA grading report.
GIA Diamond Dossier: The GIA Diamond Dossier offers identical grading information that of the GIA Diamond Grading Report, minus the plotted diagram. With an added security feature, the GIA Diamond Dossier service includes microscopic laser inscription of the report number on the diamond's girdle.
The GIA laboratory issues Diamond Dossiers for loose, fully natural diamonds in the D-Z color range, weighing 0.15 carat to 1.99 carat. The GIA Diamond Dossier is NOT issued to diamonds that have undergone unstable treatments. Stable treatments are noted on the GIA Diamond Dossier.
www.gia.edu/
European Gemological Laboratory Israel (EGL Israel)
EGL certificates are recognized around the globe for their accuracy and integrity, defining industry standards in evaluation and appraisal.
The company maintains a worldwide presence in the major diamond trading centers, cooperates with leading organizations including the World Federation of Diamond Bourses and runs an extensive educational program as part of its dedication to protecting public interest and raising the level of professionalism in the field.
EGL Diamond Certification Full Page Report: The EGL Diamond Certification Full Page Report includes the following:
- Assessment of a diamond's 4 C's = color, clarity, cut, and carat weight
- Plotted diagram of clarity characteristics.
- Free UGS Consultation of Appraisal
- Security features = lamination, embossed logo, hologram
- Transparent sleeve packaging
- 8.5 x 11"open page view
EGL Diamond Analysis Full Page Report: This report contains identical information to the EGL Diamond Certification Full Page Report, but is ONLY issued to round stones and also includes the following features:
- Final prominent cut grade
- Emphasized proportions in graphic profile view
- Free UGS Consultation of Appraisal with retail replacement value
- Laminated with hard-vinyl packing and EGL USA embossed logo
- 8.5 x 11" open page view
EGL Diamond Certificate Mini Sized Report: This is a smaller, condensed version of the Diamond Certificate Report. This contains all proportion and finishing information and includes the following:
- Assessment of the diamond's 4 C's = color, clarity, cut, and carat weight
- Finished proportion and measurements
- Includes Diamond Consultation with a plotted diagram
- 4 x 3.25" page view
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