Jewelry and Gems The Buying Guide: Diamond Grading Report

Today, few fine diamonds over one carat are sold with out a diamond grading file, or certificates, as they are also called, from a reputable laboratory. Reports issued through the GIA/Gem alternate laboratory are most extensively used within the United States and many nations around international.
A grading document does extra than make clear the stone’s genuineness, it completely describes the stone and evaluate every of the essential elements affecting great, splendor, and fee. Grading reviews may be very useful for a diffusion of reasons. The facts they include can offer verification of the “statistics” as represented by means of the vendor and permit one to make a safer choice whilst shopping a diamond. Another, essential characteristic of news is to confirm the identity of a specific diamond at a few destiny time, if, for instance, it has been out of one’s ownership for any reason. For insurance functions, the facts furnished at the document will help make certain alternative of a lost or stolen diamond with one this is in reality “like minded pleasant.”

Reports are not essential for each diamond, and many beautiful diamonds utilized in earrings are sold with out them. But while considering the purchase of a totally first-class diamond weighting one carat or extra, we strongly endorse that the diamond be observed via a report, despite the fact that it way having a diamond eliminated from its setting (no respectable lab will trouble a report on a mounted diamond), after which reset. If you are thinking about a diamond that lacks a document, it is simple to your jeweler to obtain one. Or, now that GIA is issuing diamond grading reports to the general public, you could put up a diamond at GIA yourself.

Do no longer rely on the document on my own

The availability and considerable use of diamond grading reviews can, when well understood, allow even the ones with out professional skills to make legitimate comparisons between numerous stones, and for that reason make extra knowledgeable buying choices. Reports may be an important tool to help you apprehend variations affecting rate. But we have to caution you now not to let them interfere with what you want or actually need. Remember, some diamonds are very beautiful even though they don’t adhere to set up standards. In the final analysis, use your own eyes and ask your self how you want the stone.

A purchaser who turned into looking to determine among several diamonds. Her husband desired to shop for her the stone with the great record, however she favored another stone which, in keeping with what turned into at the reviews, wasn’t as exact. They determine against the excellent diamond and purchased the only that made her happiest. The critical thing is they knew precisely what they had been shopping for, and paid the correct fee for that specific combination of high-quality elements. In different phrases, they made an informed choice. The reviews gave them assurance as to the data, and extra self belief that they knew what they had been absolutely evaluating.

Improper use of stories can lead to high priced errors

As crucial s diamond grading reviews may be, they also can be misused and result in misguided conclusions and expensive mistakes. The key to being capable of depend on a diamond file, and having confidence to your selection, lies in understanding the way to examine it nicely. For instance, while looking to determine among diamonds accompanied through diamond grading reviews, buyers all too frequently make a decision by way of comparing simply elements evaluated on the reviews, coloration and clarity, and think they have got made a valid choice. This is rarely the case. No you’ll be able to make a legitimate choice based on coloration and clarity alone. In fact, whilst large price differences exists among stones of the equal colour and clarity as the extra high priced stone, and often it isn’t the better cost. Having the same coloration and readability is best a part of the total image. Differences in price suggests variations in high-quality, variations you could not see or apprehend. With spherical diamonds, the statistics you need is on the report, but you want to apprehend what all of the statistics means before you could make legitimate comparisons.

A phrase of warning: Do no longer make a purchase depending completely on any report with out making sure the record fits the diamond, and that the diamond remains inside the equal circumstance defined. Always are seeking for a professional gemologist, gemologist-appraiser, or gem-trying out laboratory to verify that the stone accompanying record is, in fact, the stone defined there, and that the stone continues to be in the equal circumstance indicated on the record. There are times wherein a report has been by chance sent with the wrong stone. And, in a few cases, deliberate fraud is worried.

How to read a diamond grading record

Check the date issued. It is very important to check the date at the document. It’s always viable that the diamond has been broken for the reason that file changed into issued. This once in a while occurs with diamonds offered at auction. Since diamonds can emerge as chipped or cracked with wear, one must always check them. For example, you may see a diamond observed by way of a file describing it as D – Flawless. If this stone had been badly chipped after the file changed into issued, however, the readability grade may want to without difficulty drop to VVS, and in a few instances, a lot decrease. Needless to mention, in this type of case cost would be dramatically decreased.

Who issued the document? Check the call of the laboratory issuing the record. Is the record from a laboratory this is known and revered? If now not, the information at the document may not be reliable. Several properly-respected laboratories problem reviews on diamonds. The quality recognised within the United States include the Gemological Institute of America Gem Trade Laboratory (GIA/GTL or GIA), and the American Gemological Laboratories (AGL). Respected European labs issuing reviews encompass the Belgian Diamond High Council (HRD). Regardless of which document you are studying, all will offer comparable data, together with:

Identity of the stone. This verifies that the stone is a diamond. Some diamond reviews do not make a particular assertion approximately identity due to the fact they’re referred to as diamond reviews and are most effective issued for proper diamonds. If the report isn’t referred to as a “diamond grading document” then there must be a statement attesting that it is genuine diamond.

Weight. The genuine carat weight should be given.

Dimensions. Any diamond, of any shape, ought to be measured and the dimensions recorded as a way of identity, especially for coverage/identification purposes. The dimensions given on a diamond file are very costs and provide records that is essential for numerous motives. First, the dimensions permit you to determine that the diamond being tested is, in reality, the equal diamond described inside the record, since the chance of getting diamonds with precisely the equal carat weight and millimeter dimensions is remote. Second, if the diamond has been broken and re-reduce for the reason that report become issued, the millimeter dimensions can also offer a clue that something has been altered, which might have an effect on the carat weight as nicely. Any discrepancy between the measurement which you or your jeweler get by way of measuring the stone, and those provided on the report, should be a pink flag to check the stone very cautiously.

Finally, the dimensions on the record additionally let you know whether or not the stone is spherical or out of spherical. Out of round diamonds sell for less than the ones which can be extra perfectly round.

Fine diamonds are “well-rounded”.

The diamond’s roundness will have an effect on fee, so it’s miles decided very cautiously from measurements of the stone’s diameter, gauged at several factors round across the circumference. For a round diamond, the report will generally supply diameters, measured in millimeters and stated to the hundredth: for example, 6.51 in place of 6.Five; or 6.07 rather than 6.Zero. These imply the best and lowest diameter. Diamonds are very hardly ever perfectly spherical, which is why maximum diamond reports will display measurements. Recognizing the rarity of actually spherical diamonds, a few deviation is permitted, and the stone will no longer be considered “out of round” until it deviates via greater than the installed norm, about 0.10 millimeter in a one carat stone. In a one carat diamond, if the difference is 0.10 or much less, then the stone is taken into consideration “spherical.” If the difference is greater, it’s far “out-of-spherical.”

To calculate an appropriate deviation on a specific stone, common the high and the low diameter measurement given and multiply that wide variety by means of zero.0154. For instance, if the size given are 8.20x 8.31, the diameter average is 8.25 ( (8.20 + eight.31)/2). Multiply eight.25 via zero.0154 = zero.127. This is the appropriate deviation allowable for this stone (between 0.12 and zero.Thirteen). The actual deviation in this example would be 0.Eleven (eight.31 – eight.20), properly in the tolerance, so this diamond could be taken into consideration “spherical.” Some flexibility is allowed on diamonds over two carats.

Depending on diploma of out-of-roundness (how a good deal it deviates from being perfectly spherical), fee may be affected. The greater the deviation, the lower the price should be.

Dimensions for fancy shapes

While measurement for fancy shapes diamonds are not as critical as they may be for round diamonds, there are length to width ratios that are considered “regular” and deviations may additionally bring about charge discounts. The following reflect acceptable stages:

Pear form: 1.50:1 to one.Seventy five:1

Marquise shape: 1.Seventy five:1 to two.25:1

Emerald form: 1.50:1 to one.75:1

Oval shape: 1.50:1 to 1.Seventy five:1

To higher understand what this means, allow’s examine a marquise diamond as an example. If its report confirmed the length to be 15 millimeters and the width to be 10 millimeters the length to width ratio could be 15 to ten or 1.5:1. This would be proper. If, but, the scale have been 30 mm lengthy with the aid of 10 mm wide, the ratio could be 30 to ten or three:1. This would be unacceptable; the ratio is too incredible, and the result is a stone that looks a whole lot too lengthy for its width. Note: A long marquise isn’t always terrible, and some human beings decide upon a longer shape, however it’s miles important to take into account that such stones must sell for much less than those with everyday lengths. Always preserve in thoughts the period to width ratio of fancy cuts, and regulate the charge for that are not in the proper variety.

Evaluating proportioning from the document

As discussed earlier, proper proportioning is as crucial to diamond as it is to the character who wears it! The proportioning, specially the intensity percentage and desk percentage, s what determines how brilliance and fireplace the stone could have.

The records supplied on diamond reports pertaining to proportions is severely critical for round, incredible reduce diamonds. Unfortunately, it’s miles handiest of minimum use with fancy fancy form diamonds. For fancies, you must discover ways to depend on your eye to inform whether or not or no longer the proportioning is suitable: are there variations in brilliance across the stone? Or flatness? Or darkish spots inclusive of “bow-ties” attributable to bad proportioning.

Evaluating the proportioning of a diamond is as important as comparing the shade and readability grades. Diamonds which can be cut near “perfect” proportions, stones with “splendid” makes can easily cost extra than the norm at the same time as diamonds with bad makes sell for much less; very badly proportioned stones ought to be priced for a lot less. The records on a diamond document permit you to evaluate the proportioning and recognize whether or not or no longer you ought to be paying greater, or much less, for a specific diamond.

Depth percentage and Table percent key to splendor

To determine whether or not or no longer a spherical stone’s proportioning, so crucial to its beauty, is ideal, take a look at the phase of the report that describes depth percentage and table percent. The intensity percent represents the depth of the stone, the gap from the desk to the culet, as a percent of the width of the stone. The desk percentage represents the width of the desk as a percent of the width of the complete stone. These numbers suggest how well a spherical stone has been cut in terms of its proportioning, and must adhere to very unique standards. Your eye can be able to see differences in sparkle and brilliance, however you may now not be capable of figure the subtleties of proportioning. The percentages on the document need to fall inside a fairly specific range so as for the stone to be judged appropriate, terrific, or poor.

Some reports additionally offer information about the crown perspective. The crown attitude tells you the attitude at which the crown portion has been cut. This attitude will affect the depth and desk percent. Normally, if the crown attitude is between 34 and 36 levels, the table and depth will be notable; between 32 and 34, exact; among 30 and 32 tiers, fair; and much less than 30 levels, negative. If the precise crown attitude is given, it is probably considered acceptable. If no longer, there’s a announcement indicating that crown attitude exceeds 36 ranges, or is much less than 30 ranges.

Depth percentage

A spherical diamond cut with a depth percentage among fifty eight and 64 percentage is generally a lovely, lively stone. You have to be aware, however, that girdle thickness will affect depth percentage. A excessive intensity percentage may want to end result from a thick or very thick girdle, so when checking depth percentage on the diamond file, take a look at the girdle records as well.
Stones with a intensity percent over 64% or below fifty seven% will generally be too deep or too shallow to showcase most beauty and need to promote for much less. If the intensity percent is just too excessive, the stone will appearance smaller than its weight indicates. If the intensity percent is rather excessive, brilliance may be notably affected. Diamonds which can be so shallow, that is, stones with such low intensity possibilities, that they have no brilliance and liveliness in any respect. When dirty, such stones look no better than a bit of glass.

We keep away from diamonds with depth percentages over sixty four% or underneath 57%. If you are attracted to such diamonds remember the fact that they need to promote for much much less in step with carat.

Table Percentage

Round diamonds reduce with tables starting from 53% – 64% typically bring about beautiful, energetic stones. Diamonds with smaller tables usually exhibit extra fire than those with large tables, however stones with large tables may additionally have greater brilliance. As you spot, desk width impacts the diamond’s persona, however identifying which personality is greater acceptable is a matter of private taste.


Under end at the diamond file, you may discover an evaluation of the diamond’s polish and symmetry. Polish serves as a hallmark of the care taken by way of the cutter. The quality of the stone’s polish is a aspect that cannot be ignored in comparing the overall best of a diamond, as well as its fee and value. Polish can be defined on the record as excellent, excellent, excellent, fair, or negative. The price in step with carat should be much less on diamonds with “fair” or “negative” polish. Cost in step with carat is commonly greater for diamonds which have “superb” or “outstanding” Polish.
Symmetry describes numerous factors:

How the aspect edges align with each other;
whether or not or not the sides from one side of the diamond healthy corresponding facets on the other facet;
whether or not or not sides in the top portion of the diamond are properly aligned with corresponding ones in the backside element.

When the symmetry is defined as “honest”, or worse, something is out of line.
When evaluating symmetry, the most essential location to check is the alignment of the crown (pinnacle) to the pavilion (bottom). If it isn’t always true, it’s going to make a visual difference inside the splendor of the stone, and correspondingly in its charge. To test for correct alignment here, virtually take a look at the diamond from the aspect to peer whether or not or no longer the aspects just above the girdle align with the facets just under the girdle.

When the pinnacle and bottom facets do not line up, it shows sloppy slicing and, extra crucial, the overall splendor of the diamond’s is faded. This will reduce the fee extra than different symmetry faults.

How does the girdle affect cost?

The girdle is some other crucial object defined on diamond grading reviews. The file will suggest whether or not or no longer the girdle is polished, or faceted, and how thick it is. Girdle thickness ie very vital for two motives:

It influences value, and
It impacts the diamond durability.
Girdle thickness levels from extremely skinny to extremely thick. Diamonds with girdles which are excessively thin or thick normally sell for much less than other diamonds. An extraordinarily thin girdle will increase the threat of chipping. Remember that notwithstanding their mythical hardness, diamonds are brittle, so very thin part poses a greater risk.

If a diamond has an incredibly thick girdle, its price ought to also be reduced relatively because the stone will look smaller than another diamond of the identical weight with a greater normal girdle thickness. This is because extra weight is being fed on via the thickness of the girdle itself.
There are some cases in which a completely thick girdle is acceptable. Shapes that have one or greater factors, inclusive of the pear form, coronary heart, or marquise, may have thick to very thick girdles in region of the factors and nevertheless be within the proper range. Here the greater thickness inside the girdle helps defend the factors themselves from chipping.

Generally, a diamond with an extremely thin girdle should promote for less than one with a very thick girdle due to the diamond’s expanded vulnerability to chipping. However, if the girdle is a lot too thick (as in older diamonds), the rate can also be substantially less because the stone cam appearance considerably smaller than other diamonds of comparable weight.

The Culet

The culet seems like a point at the lowest of the diamond, however it’s miles normally some other side, a tiny, flat polish floor. This facet ought to be small or very small. A small or very small culet won’t be noticeable from the pinnacle. Some diamonds, these days, are pointed. This method that there simply isn’t any culet, that the stone has been cut instantly down to a degree as a substitute. The large the culet, the extra seen it will be form the top. The extra seen, the decrease the value of the diamond. Diamond defined as having large or “open” culet as in vintage European or old-mine cut diamonds are less desirable, due to the fact the appearance of the culet reasons a reduction in sparkle or brilliance at the very center of the stone. These stones usually want to be re-reduce, and their price have to take the need for re-reducing. For the identical reasons, a chipped or damaged culet will critically detract from the stone’s beauty and significantly lessen the value.

Color and Clarity

The shade and clarity grades on a diamond record are the gadgets most people are acquainted with. They are important elements in phrases of figuring out the value of a diamond, however as the preceding dialogue has shown, they do now not tell the whole tale approximately the diamond.

A phrase approximately fluorescence

Fluorescence, if gift, can also be indicated on a diamond grading file. It may be graded vulnerable, moderate, sturdy, or very sturdy. Some reviews imply the color of the fluorescence as blue, yellow, white, and so on. If fluorescence is slight to very sturdy and the shade is not indicated, you must ask the jeweler to inform you what colour the stone fluoresces. A stone with robust yellow fluorescence should sell for less considering that it’s going to appear extra yellow than it really is while worn in daytime or fluorescent lighting. The presence of blue fluorescence will now not detract, and in some cases can be considered an advantage considering the fact that it is able to make the stone appear greater white than it sincerely is in daylight hours or fluorescent lighting fixtures. However, if the file show a completely strong blue fluorescence, there can be an oily or milky look to the diamond. If the stone seems milky or oily to you as you have a look at it, mainly in sunlight hours or fluorescent light, it ought to promote for much less.

Pay attention to the full readability photograph furnished

The placement, number, type, and colour of inner and external flaws can be indicated on a diamond grading file, may encompass a plotting, d diagram displaying all the information. Be positive you carefully note all the details further to the cumulative grade. Remember, the position of imperfections can affect value.

A dependable diamond grading report can’t be issued on a fracture-filled diamond, so GIA and most other labs will now not problem a document on diamonds which have been clarity more advantageous by way of this method. The diamond could be again with a notation that it’s far crammed and can’t be graded. Reports are issued on diamonds which have been clarity improved by means of laser. Remember, but, that regardless of what the readability grade, a lasered diamond have to no longer cost less than another with the same grade.

A final word approximately diamond reports

Diamond grading reviews offer a totally useful tool to useful resource in comparing diamonds and evaluating excellent and cost. But the important thing to their usefulness is right understanding of how to examine them, and a way to have a look at the stone. Those who make an effort to examine and apprehend what they’re studying and, consequently, what they’re without a doubt buying, can have a primary gain over those who do now not.

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Bijan Aziz is the proprietor and Web Master for The Jewelry Hut.