Tag: Symmetry

How to Read a GIA Diamond Grading Report

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So you’re ready to propose to the love-of-your-life with a Knox Custom Engagement Ring, but you want to be positive you’ve chosen the best possible diamond. Knox Jewelers recommends selecting a diamond evaluated by GIA to ensure the diamond comes with a detailed graded report. A GIA Diamond Grading Report is the standard for evaluating diamonds and their quality. Don’t know how to read a GIA Diamond Grading Report? Don’t worry, Knox will always help you learn everything about your diamond selection, either in-store or online.

GIA stands for Gemological Institute of America. It is a public and independent benefit institute that was established in 1931. They are the leading source of knowledge, standards, and education when it comes to gems and jewelry. GIA is the creator of the “4 Cs” (Color, Clarity, Cut, and Carat Weight) and the International Diamond Grading System that maintains the methods and best practices for describing diamond quality. Today, virtually everyone in the international diamond industry uses these methods for comparing and evaluating diamonds. A grading report from GIA is more than a collection of observations about a gem. It represents an accurate and unbiased, comprehensive scientific investigation.

Let’s review the main components of a GIA grading report.

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Each diamond evaluated by GIA is assigned a unique GIA Report Number which you can use to look up your report online.

A diamond’s Shape refers to its face-up outline.  Popular shapes include round, square, oval, rectangle and pear.

Cutting Style refers to a stone’s faceting pattern. Brilliant-Cut diamonds contain a large number of small, triangular shaped facets. These include Round Brilliant, Princess and Ovals cut gems. Step-Cut diamonds contain larger, long, rectangle shaped facets.  These include Emerald and Asscher cut gems.

A diamond’s Measurements will be listed in the order of smallest width, largest width and height.

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The Weight of a diamond is measured in a form called carats. GIA reports a diamond’s carat weight to the nearest hundredth of a carat. To give you some perceptive, 1 carat is equal to 0.20 grams.

The GIA Color Grade system describes the diamond’s lack of color by ranging from the denotation D, which is colorless, all the way to Z, which will be a shade of either light yellow or brown. Color grades from D to F are considered colorless diamonds and G to J are near-colorless.

Diamond Clarity evaluates the size, the number, relief, nature, and position of internal inclusions and surface blemishes. The Institute assigns one of eleven clarity grades to a diamond. This can range from the clarity grade of flawless to that of included and lists the most prominent clarity characteristics. Stone graded VS2 and above should be eye-clean, with inclusions only seen under magnification.

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On some report formats, Clarity Characteristics are shown as a plotted diagram, marking significant or identifying characteristics. A key lists the relevant symbols and their definitions. Red symbols stand for inclusions, which characteristics inside a stone. Green or black symbols stand for external characteristics on the diamond, or blemishes.

For the standard round brilliant diamond, GIA assigns a Cut Grade ranging from Excellent to Poor. Diamonds can be Excellent, Very Good, Good, Fair, or Poor. This grading takes into account seven components; Polish, Symmetry, Weight Ratio, Durability, Brightness, Fire, and Scintillation.

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The diamond’s Proportions are thoroughly described as well, from its shape and cutting style to its precise measurements. A diagram will show you the diamond’s profile as well as its dimensions.

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A description of Fluorescence is provided as an additional identifying characteristic. GIA tests every diamond to ensure that it is natural and to identify any processes that may have been used to alter its color or clarity. An asterisk next to the color or clarity grade indicates that the diamond has been treated. Treatments and additional identifying characteristics are described in the comments section.

If the diamond is inscribed, the Inscription will be noted on the report as well. A GIA Grading Report has a number of sophisticated security features designed to ensure its authenticity and integrity. They offer a variety of diamond reports, among them the Diamond eReport, an interactive online option available only for natural and untreated diamonds(perfect if you want to search for beautiful custom diamond engagement rings from the comfort of your home). The Institute operates under strict standard procedures and principles designed to ensure objectivity and accuracy, no matter which report you receive.

That’s how to read a GIA Diamond Grading Report! It’s not as intimidating as you might think. Selecting the perfect ring among many beautiful custom diamond engagement rings might be another story. Luckily, Knox Jewelers can help you look at a variety of rings and narrow it down to the perfect one for your lucky life partner. GIA Diamond Grading Reports are also available! Let Knox Jewelers help you learn about diamonds so you can pick the perfect diamond that meets the color, clarity, cut, and carat weight that you desire and help give your engagement a beautiful start.

How Diamond Cut Grade Affects Fire, Sparkle, Scintillation

Have you ever looked at a diamond and wondered why some diamonds are more attractive than others? While some are bright and flash with a rainbow of colors, others look dark and lifeless? These differences are all based on the cut and shape of a diamond. Cut grade fuels a diamond’s overall visual appeal in fire, sparkle and scintillation.

The light behavior within a diamond directly correlates to how well a diamond is cut. GIA recognized this relationship of a diamond’s cut and the quality of fire and the return of white light. Developing a grading system that quantifies specific measurements, angles, and percentages GIA was able to determine parameters that embody the best qualities in the cut of a diamond.

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GIA's Diamond Cut Grade: Example of a Round Brilliant Excellent Cut and Poor Cut

GIA began their 15 year study on the round brilliant by creating a computer model to examine light behavior within a diamond. Developing proportion-based metrics from this model they were able to predict a diamond’s performance on fire and brilliance. However, research proved that computer-based results could not be the only determining factor in judging a diamond’s overall brightness. After surveying industry leaders and general consumers, GIA created a foundation for the round brilliant cut grade.

When a cut grade is given, it is the component of brightness, fire, scintillation, polish, and symmetry, as well as durability and weight concerns. These are all an integral part that make up the GIA diamond cut grade system. With many different proportion combinations possible, GIA was able to determine the relationship of a stone’s interaction with light.

The reflection of light internally and externally in a diamond is called it’s brilliance. Fire is the dispersion of spectrum colors you see when light hits the diamond. The pattern of light and dark areas and the flash of light that emits when a diamond is moved is called scintillation. A well cut diamond will attribute to these three desired qualities because it directs more light through the top of the stone. A poor cut will appear dark because light is exiting through the bottom of the stone if it is too deep or too shallow.

Diamond cut is often confused with its shape. Round, used in most diamond jewelery, is the shape of a stone. All other shapes are classified under fancy shapes. Evaluated only on polish and symmetry, fancy shapes do not receive a cut grade like the round brilliant. These grades are valued ranging from Excellent to Poor.

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GIA's Diamond Shape: Round Brilliant and Fancy Shapes

Polish is rated on the overall surface condition of a diamond’s facets. It is the result of the polishing process and blemishes created after cutting. These grades are given to a diamond when viewed under 10X magnification. An Excellent or Very Good may have minute or minor features that can only be seen with the aid of a microscope. Anything Good or lower can affect the appearance of a diamond and may be seen by the naked eye.

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GIA's Diamond Cut Grade: Example of Poor Polish

Symmetry is the exactness of shape and placement of the facets. It is subdivided into two types of features, proportion-related and facet-related. These grades are also performed under 10X magnification for its initial face-up impression and profile view. Both angles are evaluated because of the three dimensional nature of a diamond; one symmetry feature can be linked to others. Similar to polish, grades given Good or lower can have symmetry features that are noticeable to the unaided eye.

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GIA's Diamond Cut Grade: Example of Poor Symmetry

Understanding GIA parameters for each grade and the specific guidelines they represent, Knox Jewelers recommends fancy shapes to be Good or Better. With almost 30 years of industry experience, we have found that the beauty of a diamond is greatly reduced when selecting polish or symmetry below this standard. A diamond that contains Good or Better qualities enhances the elegance of a handmade Knox custom design.

The care and craftsmanship that goes into each ring is harmonious to the quality of diamond a customer chooses. As the focal point, a diamond captivates the attention with its radiance of sparkle and luster. Selecting a well cut stone to compliment a Knox diamond engagement ring is a timeless expression of love, forever evoking a sense of glamor and romance.