GIA Archives - Knox Jewelers

What is a Round Brilliant Cut?

Definition

A Round Brilliant Cut is the modern era’s most popular selection for diamond jewelry. This perfected cut represents six generations of skilled cutters’ efforts to create the maximum light return in a diamond. A Brilliant Cut has a circular outline and a cone-like shape, with faceting patterns that create areas of light and dark contrast. Its triangular and quadrilateral facets are strategically placed to provide exceptional scintillation through the top facet of the gemstone, or its table. The faceting pattern of the modern Round Brilliant was developed in 1919 by Marcel Tolkowsky. Hailing from a family of diamond cutters, Marcel’s cut is based off mathematical calculations that took into account both the maximum brilliance and fire of a diamond. It is referenced to as a ‘Round Brilliant’ to distinguish it from earlier round shaped diamond cuts. The modern round cut consists or either 57 or 58 facets. There are 33 on its crown, or top, and 25 on its pavilion, or bottom. A round brilliant may or may not include a culet, or the bottom-most point facet. Tolkowsky found that if a diamond is cut too shallow or too deep light can escape out of the side or bottom of the gemstone, resulting in the loss of brilliance and fire.

Round Brilliant Facet Diagram

Considering a Round Brilliant Cut

Round Brilliant Cut diamonds are admired for their exceptional fire and modern aesthetic. Nearly 75% of diamonds sold in today’s marketplace are round shaped. The Gemological Institute of America, or GIA, introduced the 4Cs grading system to judge diamonds, with its cut grade exclusively created to evaluate Round Brilliant diamonds. A cut grade will determine how well a gemstone interacts with light. A well-cut diamond will reflect light within itself, from one mirror-like facet to another. If a diamond is dark it means it has been cut too deep or too shallow and light is being lost through the side or bottom. This reduces its brilliance and value, and for this reason we recommend a cut grade of no lower than Excellent or Very Good when shopping for a Round Brilliant diamond.

A Round Brilliant’s faceting pattern will hide a small amounts of body color when face up, but we still recommend choosing a diamond above a I color grade to insure a near colorless stone. When selecting a clarity grade for a Round Brilliant we recommend anything in the VS1 to SI2 range. A stone graded above an SI1 should be eye clean. Clear diamonds can be found in the SI1 and SI2 range, but it is best to evaluate them in person to determine if their characteristics are distracting or unnoticeable.

Knox Jewelers is here to help you create a one-of-a-kind custom engagement ring. If you are considering a Round Brilliant center stone, our design consultants can walk you through all of your options and help you choose your perfect diamond. Contact us today to get started on your custom design.

How to Read a GIA Diamond Grading Report

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.

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.

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.

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.

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.

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.

Knox Jewelers Minnesota – Understanding Diamond Fluorescence

Fluorescence or not to fluorescence? That is the question. Have you ever taken a look at a diamond grading report and wondered what does it mean when it says “Fluorescence?” Listed under the 4C’s you find Additional Grading Information and discover a section listed fluorescence. First, let’s take a look at what fluorescence is.

gia_grading_report_additional_info-300x141 Diamonds — GIA Additional Grading Info - Fluorescence

The formation of a diamond is how fluorescence exists in some stones. As a diamond grows in the earth, many defects occur during this formation. Nitrogen related defects are common during this process and if a growing diamond crystal captures surrounding nitrogen, the nitrogen resides within the crystal and it can result in fluorescence. There are various known colors of fluorescence, most commonly found is blue. Although many in the industry view fluorescence as a negative effect, research has proven otherwise.

Fluorescence in a diamond is an emission of light viewed under the concentration of long-wave ultraviolet radiation of a UV lamp. The appearance of fluorescence in a diamond continues as long as it’s exposed under radiation, and not under normal lighting conditions. The strength of fluorescence is graded on a range of none, faint, medium, strong and very strong.

diamond_fluorescence-300x185 Diamonds — Diamond Fluorescence via GIA Study

Let’s see what are experts at GIA have to say regarding fluorescence. As the premier laboratory in diamond grading, GIA is widely respected world-wide and sets industry standards. They are highly recognized for strict diamond grading practices and continued research in gemology. As a leader in the industry, Knox Jewelers believes in this highly respected laboratory and primarily sells GIA diamonds.

Published in 1997 in GIA’s quarterly journal, Gem’s and Gemology, they offered insight on diamond fluorescence titled “A contribution to Understanding the Effect of Blue Fluorescence on the Appearance of a Diamond.” The relationship of detecting fluorescence in a diamond was observed in a series of experiments. The study consisted of trained graders, industry professionals, and general observers using very similar sets of four round brilliant diamonds. The diamonds ranged in color of near colorless to faint yellow and diamonds were selected with varying strengths of fluorescence in the diamond color they typically represent. The observers then viewed the stones in various positions and lighting environments.

The general observers in this experiment represented the average jewelry consumer. When they viewed the diamonds in standard light, the effect of fluorescence was not detected. Even experienced individuals within the jewelry industry did not consistently agreed upon the effects of fluorescence from one stone to another. At the end, the results proved that most observers saw no correlation between fluorescence and transparency.

This study revealed that strong blue fluorescent diamonds actually appeared better in color when viewed face-up, with no noticeable trend when the diamond was facing down. Other sources report that diamonds in lower color grades, I-N, with fluorescence tend to offset the body color of these stones. The fluorescence will actually mask the faint to light yellow color of a diamond.

However, not all diamonds will have this effect with fluorescence. Some will actually appear milky in transparency. This hazy appearance attributes to the negative perception of fluorescence. Diamonds graded with fluorescence can often reflect lower values than those of similar quality with no fluorescence.

At Knox, our recommend diamond range where quality meets value, does include fluorescence. If fluorescence is present in a diamond and does not hinder the overall beauty of a stone, it can sometimes be a better value. Diamonds with fluorescence may appear to the viewer better in color than the grade it was given and save money for our customers. A great value for your investment.

Knox Jewelers can guide you through GIA diamond reports, from the 4C’s to fluorescence or any questions you have. Visit one of our convenient metro locations, if you’re in Minneapolis check out our Uptown location. Living in St. Paul, our Woodbury gallery is located right off of I-94.