Going Beyond the Grading Report

As a gemologist and diamond salesperson, one of the most common mistakes I find clients making when shopping for diamonds is that they compare diamonds on the basis of the certificate ("cert"; grading report) alone.  I tell my clients that, as cliche as it sounds, a diamond is more than the sum of its parts.  Grading reports are a great assurance to the consumer of the quality and authenticity of the diamond that they are purchasing, but they are limited in their use.

Imagine for a moment that you are in a diamond showroom and the salesperson brings out ten diamonds of the same color and clarity and all with grading reports from the same laboratory.  The carat weights are all quite similar, varying in only a few points, and all of them received Excellent cut grades.  Each grading report you read seems to look like a copy of the last one that you saw.  How are you going to choose which diamond is best buy for you when you cannot base your decision solely on the reports?  You look at the diamonds laid out in front of you, and you see that they strike you differently.  The store's gemologist shows you each stone under a gemological microscope and you see that although each is VS1-clarity, their internal characteristics look quite different.  Some seem to have brighter, more white flashes and others are very fiery and colorful.  What you have done now is you are looking into the heart of each diamond.  You are buying based on which diamonds speak most to you.  You have gone beyond the grading report.

Well, what does this mean for you, the consumer?  It means that although there are many outlets for you to see scores of diamonds ranked by the details of their grading reports alone, you are missing the true visual element of each stone.  Use those outlets to narrow your quality parameters to best match your price range.  Decide on what approximate carat weights are most affordable for you.  Then, bring this information to your trusted jeweler, and go beyond the grading report and into the beauty of the diamond.  After all, when a woman wears her stunning new piece of diamond jewelry, it is this beauty you see, not the grading report.

Originally posted by me to LibertyDiamonds.com on 3/9/2010.

From the Gemologist: More about Clarity

How a Clarity Grade is Assigned

When a trained diamond grader is evaluating a diamond for its clarity, he or she will view the stone with the naked eye and with 10x magnification to assess the overall impact of the diamond's clarity characteristics.  External characteristics do not affect the clarity grade below Internally Flawless (IF).  They will, however, factor into the polish grade.  There are many types of internal characteristics, but here is an brief explanation of the most common ones you will see:

  • Crystal - A foreign crystal trapped inside the diamond during the growth process
  • Feather - A break inside the diamond that is caused by blunt force or pressure applied to the stone
  • Pinpoint - A tiny crystal that appears literally no larger than a pinpoint when viewed at 10x magnification
  • Cloud - A series of pinpoints grouped together
  • Needle - An included crystal shaped like a rod
  • Indented Natural - A portion of the skin of the rough diamond crystal that falls below the polished surface of the diamond

After identifying all of the inclusions visible under 10x magnification, the grader then assesses the overall impact of the internal characteristic(s) based on five factors:

  • Size - How small or large is/are the inclusion(s)?
  • Number - How many inclusions are inside the diamond?
  • Position - Where are the inclusions located?
  • Nature - What type of inclusion(s) is/are present?
  • Relief - What is the visual impact of the inclusion(s)?

Once the diamond grader has identified the internal characteristics and assessed their impact on the diamond, he or she determines a clarity grade based on established guidelines set forth by the laboratory.

Reading Clarity on the Certificate

On the grading report for a loose diamond, you will see a single clarity grade assigned to the stone ranging from FL to I3 on the GIA scale.  Some labs such as AGS use their own nomenclature.  In addition to the clarity grade, the grading reports for most stones above one carat with be accompanied by a "diamond plot," or a map of the external and internal characteristics of the diamond.  Inclusions (most properly referred to as "internal characteristics") are found inside the diamond and are marked in red on all major laboratory reports such as GIA, AGS, and EGL.  Blemishes (or "external characteristics") are found on the surface of the diamond.  Blemishes are only noted on a grading report if the diamond is graded Flawless (FL) or Internally Flawless (FL), and they will be marked in green.

How/Why Clarity Matters

While given the choice, most women would probably want a Flawless diamond, a very high clarity grade is not needed for a diamond to be free of visible characteristics that may detract from the beauty of the stone.  Most people cannot see an inclusion with their naked eye until the diamond reaches the SI or I range.  That being said, one can still find a diamond that is essentially "eye clean" at SI1 if the stone is selected properly and by a knowledgeable diamond buyer.  For a diamond to be brilliant, it must return as much light as possible that enters the stone back to the eye.  Inclusions can interrupt the path of light and result in dull, lifeless stones regardless of the precision of the cut.  Inclusions can dramatically affect the durability of the diamond depending on their size, type, and location.  For example, a feather reaching the girdle of a diamond leaves the stone prone to chipping during the setting process or normal wear.  Keep this in mind when considering diamonds in the I range.

To select an eye clean diamond, I recommend purchasing diamonds that are grades VS2 (or perhaps SI1 if well-selected) or higher.  This way you can maximize the other three C's and get the most out of your budget.

Originally posted by me to LibertyDiamonds.com on 4/5/2010.

Cut: A Diamond’s Most Important Value Factor

"I saw the angel in the marble and carved until I set him free." - Michelangelo

A diamond cutter is like a sculptor.  He has a piece of rough diamond in front of him, and he must envision the finished diamond.  He asks himself many questions: What shape diamond will best fit this piece of rough?  Should I cut the rough into one larger diamond and sacrifice cut quality, or should I cut two diamonds of smaller size but of finer cut quality?  How can I maximize the value of the finished diamond(s) that will come from this piece of rough?  This planning stage can take days, weeks, months, even years if the piece of rough is of great importance.  He polishes a window to see into the stone, and he looks for the angel within.

Cut is the Most Important Human Contribution to a Diamond's Value

Unless a diamond undergoes treatments in a laboratory, man cannot change the color or clarity of the diamond rough.  He can just cut around inclusions and work to minimize the impact of a rough diamond's color.  The diamond cutter, however, has complete control over the cut of the diamond.  If he has a colorless, flawless rough diamond and cuts it to poor proportions, the diamond will be lifeless and dull.  But if he cuts the diamond to more exact, precise proportions with a fine finish, the angel will be set free from within the diamond.

Factors Affecting the Cut of a Diamond

There are many important factors in a diamond's cut that are precisely measured and weighed against carefully determined guidelines.  Round brilliant diamonds are the only diamonds that receive a final cut grade through the GIA cut grading system.  Polish and symmetry grades are given on all diamond cuts.  Here is a list of those factors that you will most likely come across:

  • Table size
  • Total depth percentage
  • Crown height
  • Crown angle
  • Star facet length
  • Girdle thickness percentage
  • Girdle thickness verbal description
  • Pavilion depth
  • Pavilion angle
  • Lower girdle facet length
  • Culet size
  • Polish
  • Symmetry

Each one of these factors has many different possible values that are considered in order to end up at the final cut grade.  They are all weighed equally with the exception of polish and symmetry.  Polish and symmetry grades are bumped up one grade when determining the diamond cut grade.  For example, a diamond can receive a GIA Excellent cut grade and have Very Good polish and symmetry grades.

Value of a Diamond

So how is that you can have 10 1.00-carat, G-color, VS1-clarity, round brilliant diamonds all graded by GIA and they each have different values (read: prices)?  The cut grade is most likely the answer.  All other factors being equal, a diamond with an Excellent cut grade is worth far more than one a lower cut grade.  These diamonds sell at a premium because they are the most coveted round brilliant diamonds.  A well-selected diamond with a Very Good cut grade can also be a great value, as usually there is one cut factor that through off the grade.

To maximize your diamond budget while getting the most beautiful diamond you can, I recommend a GIA cut grade of Excellent or Very Good.

Originally posted by me to LibertyDiamonds.com on 4/6/2010.

The Truth about “Carbon Spots” in Diamonds

The Myth

Walk into any jewelry store, and ask to see a diamond with eye-visible black spots.  Ask the salesperson what the spots are, and he or she is likely to tell you that they are "carbon spots," or bits of carbon, the element that makes up a diamond, that were not dissolved when the diamond was formed.  Mother Nature was boiling up some carbon to form diamonds, and some of the carbon just didn't become a diamond.  It makes sense, right?  Wrong (well, mostly wrong).

The Truth

Diamonds can have inclusions of graphite, which is carbon that formed with a different atomic structure than a diamond.  Graphite is usually a dark gray color and can definitely appear black in various lighting conditions.  But not all inclusions are created equal.  There are many different possibilities as to what a particular inclusion can actually be.  The only quick answer is that dark inclusions are included crystals (xenocrysts) that may actually be a very dark-toned red, green, brown, etc.  The only way to know for sure is to have an advanced gemological laboratory use sophisticated equipment to analyze the chemical make-up of the inclusion.

The Moral

The moral of the story is this: if you are being sold a diamond that has "carbon spots," I recommend that you run away - far, far away - and find a more knowledgeable jeweler or gemologist.  And trust me, you do not need to dip into the I-clarity range to find a diamond that maximizes your diamond budget.

Originally posted by me to LibertyDiamonds.com on 4/6/2010.

Clarity Enhancements: The Why and How

Why Clarity Enhance a Diamond?

Clarity-enhanced diamonds are interesting creatures in the diamond industry.  Some jewelers love to offer them as an affordable alternative to paying for a higher clarity grade, and others won't touch them with a 10-foot pole.  The most important point to remember about clarity enhancement is that it does not improve the clarity grade of the stone.  This might seem silly at first.  If the big black inclusions have been dissolved away or bleached out, why shouldn't the clarity grade go up?  The answer is that clarity enhancements are not natural and are not accepted as a normal part of the diamond finishing process.  They only improve the apparent clarity, or what the diamond looks like to the eye after the enhancements have been carried out.  A reputable gemological laboratory will grade the clarity of a clarity-enhanced diamond as if the inclusions were in their original state.  Ironically, these enhancements can actually worsen the clarity grade!  The purpose of clarity enhancement is to make the diamond more saleable to the consumer.  A jeweler can purchase a lower clarity diamond at a much more substantial discount than if purchasing higher clarity stones.  He or she then decides to have the diamond clarity enhanced with the ultimate aim or reaping a larger profit margin.

How Diamonds are Clarity-Enhanced

There are two main ways of enhancing the apparent clarity of a diamond: laser drilling and fracture filling.  These treatments may be appear separately or together in the same diamond.  Each method targets specific inclusions, and they are not a cure-all for included diamonds.

  • Laser Drilling - Diamonds are laser drilled in order to improve the appearance of dark, included crystals or staining caused by iron oxide.  An infared laser beam is aimed precisely at the inclusion, and it burns a microscopic hole (less than 0.2 mm wide) from the surface to the inclusion.  The heat of the laser can sometimes destroy the inclusion enough that no further treatment is necessary.  If not, the diamond is submerged in sulfuric acid dissolve the inclusion or to lighten the color of the inclusion.  Diamonds can actually have other diamonds in them as inclusions, and these cannot be removed because of diamond's immunity to sulfuric acid.  The laser leaves behind a permanent reminder of the treatment: a laser drill hole (LDH).  Laser drill holes become clarity characteristics that are taken into account when determining the clarity grade.  They are also noted on the diamond's plot.  The laser drill hole looks like a tiny tube extending into the diamond from the surface (not to be confused with a naturally-occurring growth tube).  To fill the hollow void left my the laster drilling, they might also be fracture-filled.  Laser drilling must be disclosed to the consumer.  GIA will grade laser-drilled diamonds so long as the laser drill holes have not been glass-filled.
  • Fracture Filling - Naturally-occurring breaks within a diamond can produce a white, feather-like inclusion that detracts from the beauty of the diamond.  To improve the look of these fractures, a special type of glass filling may be injected into the fractures.  The glass filling will ideally make the fractures more transparent and less noticeable.  If the fracture breaks the diamond's surface, the glass can be injected directly into it.  If the fracture is internal, a laser may be used to drill to fracture.  Laser drill holes themselves may be fracture-filled to diminish their appearance.  Fracture filling (and the accompanying laser drilling, if used) must be disclosed to the consumer.  Fracture filling is not considered a permanent treatment, as the glass come out of the diamond during normal wear, cleaning, or jewelry repairs.  Special care is required for fracture-filled diamonds.  Important: GIA will not grade fracture-filled diamonds.  This means that diamonds that are glass-filled to minimize the appearance of laser drill holes are ineligible for grading by GIA.  This is because it is not possible to accurately assess the pre-treatment clarity of the diamond.

Care and Disclosure

All diamond treatments must be disclosed to the consumer at every step of the sales process.  Diamond treatments such as fracture filling require special care and handling considerations.  These should be told to you by the jeweler.  The market for treated diamonds remains small compared to that of natural diamonds, so resaleability will be negatively affected.

Originally posted by me to LibertyDiamonds.com on 4/6/2010.

Fluorescence and Diamonds: A Love-Hate Relationship

What Is Fluorescence?

In short, fluorescence is the emission of visible light when a diamond is exposed to X-rays or ultraviolet (UV) radiation.  Roughly one third of all diamonds fluoresce to some degree.  Under the GIA grading system, diamonds are viewed in a special UV light box under long-wave UV light to assess the color and intensity of a diamond's fluorescence.  Then, one of five grades is assigned to the diamond:

  • None
  • Faint
  • Medium
  • Strong
  • Very Strong

Just like the GIA color grades, fluorescence grades encompass a range of intensities.  To prove this point, many people can notice very faint fluorescence in diamonds with a GIA grade of "None."  Besides assigning a grade commensurate with the intensity of the diamond's fluorescence, diamond graders also note the color that the diamond fluoresces.  The overwhelming majority of diamonds that fluoresce (97% in one GIA study) emit blue fluorescence.  Rarely one can find a diamond with yellow, white, or orange fluorescence.

The Effect of Fluorescence

Fluorescence is a difficult concept for many jewelry professionals to understand and explain to their clients.  Thus, the diamond industry has tended towards discounting diamonds with fluorescence grades above Medium.  Diamonds with higher fluorescence grades are more difficult to resell than those with a lower grade.  D, E, and F-color diamonds with no fluorescence command premium prices in the diamond market.  It is said that fluorescence can cause colorless diamonds to look hazy or milky in daylight, as ultraviolet radiation is present in normal daylight.  On the opposite side, blue fluorescence can improve the apparent color of a diamond with a color grade of J or below because it offsets the yellow tint of the stone.  In order to get the best value in a diamond, we recommend our clients purchase diamonds with fluorescence grades of None to Faint.

The Ugly Truth

To test the true affect of fluorescence on apparent diamond color, GIA performed an experiment where trained diamond graders, diamond industry professionals, and average consumers were shown diamonds of varying fluorescence.  The average consumers preferred diamonds that fluoresce over those that do not.  Even the trained diamond graders were mixed in their preferences of the diamonds.  Indeed, when GIA was developing its grading report, fluorescence was meant as an identifying characteristic and not as a grading factor.  GIA has determined that, at best, fluorescence has a "weak" impact (positive or negative) on the apparent color of a diamond.  But since the jewelry industry steadfastly maintains its own views on diamond fluorescence, those are the views that affect diamond value on the market.

Originally posted by me to LibertyDiamonds.com on 4/6/2010.

All About Carats/Karats

 What Is a Carat?

Well, a carat is a root vegetable that...No, sorry, we're not talking about "carrots."  The term carat refers to the generally accepted unit of measure for the mass ("weight" for common purposes) of a diamond.  The term carat is often abbreviated as "CT."  Each carat is divisible into 100 units called points.  One point equals 1/100 (0.01) of a carat.  One carat equals

  • 100 points
  • 1/5 gram
  • 200 milligrams

What Does "CTW" or "CTTW" mean?

When there are multiple diamonds or gemstones in a piece of jewelry, the total of the carat weights of all the stones are referred to a Xcarats total weight.  Carats total weight is abbreviated at CTW or CTTW.  Most jewelers have a tolerance for variation in the total carat weight established.  If the weight is approximate, the jeweler is required to specify the accepted variance.

Why aren't diamonds just weighed in grams?

Good question.  Diamonds are generally sold by their weight (mass).  A small fluctuation in weight can mean a large difference in price.  Therefore, one gram is too large of a measurement to use for the weight of diamonds.  A carat, being equal to 1/5 of a gram, is much more precise.  Diamonds weights are carried out to the second decimal place (e.g. 1.75 carats).

Does that mean all diamond weights are really just rounded?

Well, not necessarily all.  A diamond can certainly weigh, for example, 1.000 carats.  In the United States, the Federal Trade Commission (FTC) allows for diamonds to be rounded up to the next number in the second decimal place if the number in the third decimal place is a 5 or higher (e.g. 1.745 carats can be rounded to 1.75 carats).  However, GIA and many diamond dealers have set their own standard that diamond weights are only to be rounded up if the number in the third decimal place is a 9 or higher (e.g. 1.749 carats can be rounded to 1.75 carats).  This means that anything weighing, as in our example, 1.748 carats or less is rounded to just 1.74 carats.  In this way, the diamond consumer pays the fairest price for the diamond based on its weight.

So gold is weighed in carats too?

No.  Although you have undoubtedly heard terms "14 karat gold," "18 karat gold," etc., a diamond's carats have nothing to do with a gold's karats.  The term karat (with a "K" in the United States) refers to the purity of gold.  Pure gold (considered 99.9% gold or purer) is rated as 24 karats.  This is the highest possible purity rating.  When gold is referred to as "18 karats" (or "18K"), the gold is 18 out of a possible 24 karats.  This comes out to be 75% purity, and this is why some 18K gold is marked as "750" (referring to 75.0% gold content).  The other 25% is an alloy of other precious and non-precious metals used to give the gold greater strength and different color (e.g. "white gold" and "rose gold").  To make matters even more confusing, in Great Britain, for example, "karat" is spelled with a "C" making it "carat."  Therefore, there is no spelling difference between the unit of weight and the unit of purity.

Is gold really sold as low as 1 karat?

Not in the United States.  In the US, the FTC limits the sale of gold to 10 karats (58.5% gold) and purer.  Anything less than 58.5% gold cannot be legally referred to as "gold"  (The legal limit for platinum is 90.0% platinum).  Again across the pond in Great Britain, gold can be sold in as low as 9 carats (37.5% pure gold; remember the difference in spelling!).  In Italy, the minimum purity level allowed for domestic sale is 18 karats (75.0% pure gold).

Originally posted by me on LibertyDiamonds.com on 4/7/2010.

Seeing Triple? SI3 Clarity Grade Exposed

The Situation

Many consumers prepare for diamond shopping by reviewing the Four C's of diamond value as described by GIA.  After looking at the GIA clarity scale a few times, one notices that the I (Included) range is the only range with three separate clarity grades.  This is true.  But then the consumer visits some jewelry stores or looks at diamonds online and sees something that upsets what they have learned about the strictness of grading standards: the clarity grade of SI3.  SI3 is an actual grade assigned by the European Gemological Laboratory (EGL).  One can review the report for an SI3 diamond and see "SI3" actually printed on the cert.

The Problem

GIA established the internationally-recognized diamond grading system that is used by almost all gemological laboratories and members of the jewelry industry.  GIA chose not to copyright the grading system because the system was designed to unify grading standards and to instill consumer confidence in diamonds.  The GIA grading system can be used by anyone without paying royalties.  The "problem" (it is not actually a problem) with the GIA clarity scale is that the clarity ranges produce levels (FL/IF, VVS, VS, SI, and I), and the price differences between two neighboring levels can be dramatic.  In order to select a good quality diamond for an engagement ring, many jewelry professional recommend purchasing a diamond in the SI range or above.  The I range encompasses diamonds that have eye-visible inclusions, which can dramatically affect the appearance and light performance of a diamond.  Thus, a critical clarity call falls between the clarity grades of SI2 and I1.  An SI2 diamond is much more salable than an I1 stone with all other factors being equal.  So with so many diamonds being graded I1, many diamond dealers became frustrated with "borderline calls," or highly-contested clarity determinations between two grades.  Their solution: SI3.

The Truth

This newly-developed SI3 grade could be applied to the diamonds being graded as I1 but believed by some to actually be SI2.  In actuality, a grade of SI3 is, at best, an I1-clarity diamond.  There is no other way of looking at it.  EGL adopted SI3 as an accepted clarity grade in order to stay competitive with GIA and other gemological laboratories.  If a diamond dealer has a stone that he feels GIA might call an I1, he may choose to send it to EGL to get an SI3, which appears to be much more palatable to the consumer.  It would not be quite right to say that the use of SI3 constitutes fraud as EGL will actually print a grading report with "SI3" on it.  Thus, there is some backing to the grade.  There is, however, no doubt that the SI3 grade is intended to deceive the consumer.  The only organization that should have the right to alter the GIA grading system is GIA.  Altering the internationally-recognized grading system for profit is just unethical.  We at Liberty Diamonds do not accept SI3 as a legitimate grade, and we will not trade in SI3 diamonds.

My Recommendation

It is my personal recommendation to you, the consumer, to not purchase a diamond graded SI3.  Instead, opt for SI2 or I1.  The questionability of the SI3 grade will surely negatively affect the stone's actual and resale value.  It is also my personal recommendation that you reconsider accepting a grading report from a gemological laboratory that accepts the SI3 clarity grade as legitimate.