Two movies come to mind when I chose the title of this post. The first being, “Gentlemen Prefer Blondes” starring none other than the Hollywood bombshell of the day, Marilyn Monroe from 1953 where Miss Monroe sang and made famous the song, “Diamonds Are A Girl’s Best Friend”
The other film, “Breakfast at Tiffany’s” starring Academy award winner Audrey Hepburn and George Peppard. This dazzling romantic comedy was translated to the screen from Truman Capote’s best-selling novella and the “gem-like” treat set to Henry Mancini’s Oscar-winning score and Oscar-winning Mancini-Johnny Mercer song “Moon River.”
Diamonds Are A Girl’s Best Friend, so men, pay attention. What woman doesn’t like diamonds? There are a few who say they don’t however once they receive one as a token symbol of a man’s love for her, that denial quickly fades from the scene. So, before shopping for a diamond, let’s get edumecated (I guess I need to go back to school and learn how to spell).
The 4C’s
By now, I am certain that you have heard of the 4C’s when grading a diamond however here is a short review of them in order of importance when grading a diamond:
Cut – The cut of a diamond is the most important of the 4C’s because it has the most impact or influence on a diamond’s brilliance or sparkle. The cut should NOT be confused with shape of a diamond which will be discussed later in this post.
Color – Color, or the lack thereof, is the second most important characteristic of the 4C’s when grading a diamond. The less color a diamond has, the higher the grade. It used to be that colored diamonds were considered worthless or better used for industrial purposes however that has changed in today’s market where more and more individuals are choosing a colored diamond in their designs arising out of new marketing and individual preferences.
Clarity – Clarity refers to the tiny imperfections that a diamond may contain which are normally microscopic in size having appeared when the diamond was being formed by mother nature. As such Clarity is often considered the least important factor of the 4C’s. That is not to say that the diamond can have many flaws and those flaws would be overlooked in determining the grade – that simply isn’t true as flaws impact the value of a diamond probably more or equally to cut or color.
Carat Weight – The carat weight is often confused with the size of a diamond however it really refers to a diamond’s physical weight normally measured out to 5 decimal places which is normally truncated to just 2 decimal places as in .83 carats or 2.57 carats.
So, let’s take a deeper dive into the 4C’s to get a better education of diamonds before shopping for them.
4C’s – Cut
As stated above, the cut of a diamond is the most important of the 4C’s. Here’s why. There is an anatomy of a diamond, meaning its actual physical structure. This physical structure is made up of many “surfaces” known as facets. How well these facets are proportioned and positioned creating each individual diamond’s fire, sparkle and brilliance is what determines a diamond’s beauty which impacts its price or value.
Briefly, the characteristics of a well-cut diamond are its superior brilliance, fire, and scintillation (sparkle) which are defined as follows:
- Brilliance – Brilliance simply refers to the reflection of white light
- Fire – is how the light is dispersed into the colors of the rainbow so to speak
- Scintillation – is the difference of how a diamond looks when in brightly lit or dark environments – its sparkle under those conditions
The Cut – The Anatomy of a Diamond
Table: The table is the top horizontal facet of the diamond. Typically, an “Excellent” grade diamond will have a table size between 52 and 62 percent as calculated and expressed as the percent ratio between the table and the diameter of the girdle.
Total Depth: The diamond’s overall depth is measured from the top horizontal facet surface (the table) to the very bottom point of the diamond known as the culet. It too is expressed as a percentage of the average girdle diameter.
Girdle: The girdle is simply intersection of the crown and pavilion. Its thickness is usually very small however it is the location where diamonds are inscribed with their certification report number for traceability. It is the circumference of a diamond and its diameter is referenced in all relative calculations of the diamond.
Pavilion Depth: Extending from the bottom edge of the girdle to the culet is the pavilion. If the cut of the pavilion is too shallow or too deep (the pavilion depth), it will allow light to escape from the side or bottom of the diamond whereas a well-cut diamond will reflect light upward through the crown. Like other dimensions of the diamond, the pavilion depth is expressed as a percentage of the average girdle diameter.
Pavilion Angle: The importance of the pavilion angle directly influences a diamond’s brightness. The ideal angle range for an “Excellent” grade diamond is between 40.6 and 41.8 degrees, considering other parameters as well. This is calculated as an average of the pavilion main facets angles in relationship to its girdle plane.
Crown Height: The cut of the crown of a diamond can affect the dispersion of light thus affecting the brightness of a diamond. The crown height is measured from the top edge of the girdle to the table and is expressed as an average percentage to the average girdle diameter.
Crown Angle: The importance of the crown angle is that it provides a route for light entering and exiting the diamond and is formed where the bezel facets meet the girdle plane. In a well-cut diamond, the crown angle will be within 31.5 to 36.5 degrees and has a large effect on a round brilliant cut diamond’s face-up appearance.
Star Length: The star length is a horizontally projected distance from the point of the star facet to the edge of the table and is relative to the distance between the table edge and the girdle edge.
Girdle Thickness: The girdle is the narrow section of the diamond separating the crown from the pavilion functioning as the diamond’s setting edge or circumference. The girdle thickness affects a diamond in the following ways:
- A thick girdle unnecessarily adds weight to the stone where it least matters making it less desirable because it makes the diamond appear smaller.
- An extremely thin girdle, sometimes known as a knife-edge, makes a diamond more fragile and susceptible to chipping.
As such and therefore, a girdle that is “medium to slightly thick” allowing a diamond certification report number be inscribed is more preferred.
Lower Girdle / Half Facet Length: The importance of the lower girdle/half facet length is that diamonds with longer lower half facets will have more scintillation or sparkle, even though just a little. A well-cut diamond will range between 65 to 90 percent calculated by the length of the lower girdle facets relative to the length of the pavilion. This defines the contrast of a round brilliant cut diamond influencing the brilliance of a diamond.
Culet: The culet is the small facet or lack thereof found at the bottom of a diamond intended to prevent chipping and abrasion to the point. Depending upon its size which is expressed, on a certification report, as none, very small, small, medium, slightly large, large, very large, and extremely large can affect the face-up appearance. When described as none (no culet), very small or small, it falls in the excellent range on most certification reports.
4C’s – Color
Did you know that diamonds are found in almost any naturally occurring color, including gray, white, yellow, green, brown, and pink? The most valuable diamonds are colorless like a drop of pure water and is designated as a “D” color diamond.
The industry standard for grading diamonds was developed by the Gemological Institute of America (GIA) with a diamond color grades range from D (colorless) to Z (light yellow or brown).
Having said that, one might question where do the gray, black, green, pink and other yellow and brown diamonds fit into that scale? Well, naturally colored diamonds outside the normal color range are called fancy-color diamonds.
Although, here in the US, the Federal Trade Commission (FTC) provides no guidelines in using the term “fancy-color” within the jewelry industry, there is a general agreement within the international trade community as to what color range is customary for fancy-color diamonds. These are stones that are either yellow or brown diamonds having deeper color than a Z master stone OR diamonds which exhibit a color other than yellow or brown, so now you have been informed as such.
Fancy-color diamonds are found in only 1 in every 10,000 diamonds and the more intense the color, the rarer and more valuable the diamond it is and can be even more valuable than white diamonds. Fancy-colored diamonds are graded on a separate color scale than described below for obvious reasons.
Diamond color grades from D (colorless) to K (faintly colored)
D – F Color Diamonds – Colorless diamonds: The rarest and highest quality with a pure water look.
G – J Color Diamonds – Near-colorless diamonds: A great value for the quality with no discernible color
K Color Diamonds – Faint color diamonds: Budget-friendly pick; pairs beautifully with yellow gold.
So, when shopping for a diamond, whether colorless or colored, the color of a diamond you choose is based upon your budget.
4C’s – Clarity
Diamond clarity is defined as the absence of inclusions and blemishes and thus an assessment of small imperfections on the surface and within the stone. The difference between inclusions and blemishes is, inclusions are internal defects in a stone while blemishes are flaws on the surface of the stone. Realize this; diamonds are created from enormous pressure and heat within the Earth’s crust and it is only natural for them to have blemishes or inclusions.
When evaluating a diamond’s clarity, you are determining the size, number, nature, relief, and position of these imperfections, in addition to how they affect the overall appearance of the stone. No diamond is perfectly pure, however the more purity (the degree from which imperfections exist), the better its clarity.
There are 6 categories of clarity on the GIA grading scale, of which some are divided, having a total of 11 specific grades.
- Flawless (FL) No inclusions and no blemishes visible under 10x magnification
- Internally Flawless (IF) No inclusions visible under 10x magnification
- Very, Very Slightly Included (VVS1 and VVS2) Inclusions so slight they are difficult for a skilled grader to see under 10x magnification
- Very Slightly Included (VS1 and VS2) Inclusions are observed with effort under 10x magnification, but can be characterized as minor
- Slightly Included (SI1 and SI2) Inclusions are noticeable under 10x magnification
- Included (I1, I2, and I3) Inclusions are obvious under 10x magnification which may affect transparency and brilliance
To the naked eye, a VS1 and an SI2 diamond may look exactly the same. That is why an expert and accurate assessment of a diamond’s clarity performed by a trained diamond grader is extremely important. The reason I say this is because these diamonds are quite different in terms of overall quality and will contribute to a diamond’s value and price. Many inclusions and blemishes are too tiny to be seen by anyone other than a trained diamond technician, hence, why you should ask for a certification report with your purchase, whether you are purchasing loose stones or a piece of jewelry containing diamonds.
4C’s – Carat Weight
First, just what is a carat? Well a carat is a unit of measurement and is defined as 200 milligrams. So, simply put, a diamond’s carat weight is how much a diamond actually weighs as opposed to its size. Typically, larger diamonds are rarer and more desirable but two diamonds of the same carat weight can have a very different value and price depending upon the other 4C’s.
Since each carat is subdivided into 100 ‘points’, it allows for very precise measurements to the hundredth decimal place. Many times, you might hear a jeweler describe the weight of a diamond weighing below one carat by its ‘points’. For instance, for a diamond that weighs 0.25 carats, you might hear the jeweler refer to it as being ‘twenty-five points’ or calling it a ‘twenty-five pointer’. If the diamond weight is greater than a full carat (one carat), you might hear them refer to it in carats and decimals as ‘one point oh eight carats’ for a diamond carat weight of 1.08.
Below is a chart showing relative size (carat weight) of various cuts of diamonds.
Laboratory-Grown Diamonds
Today, I couldn’t leave out this subject matter even though the lab grown process didn’t even exist when the movies I referenced at the beginning of this post came out. This class of diamonds are known by several different names, namely lab-grown, lab-created, lab-made, synthetic and even engineered diamonds.
Rather than occurring in nature and mined from the earth, no matter how they are referred to as, they all refer to the fact that laboratory-grown diamonds are created in a laboratory or a factory of some sort. Since laboratory-grown diamonds have virtually the same chemical, optical, physical properties and crystalline structure as natural diamonds, some labs/factories use advanced technology to mimic the natural conditions which diamonds undergo when formed beneath the earth’s crust.
How are Diamonds Made in Labs?
There are two main processes used to create lab-grown diamonds which starts with a seed made from a tiny lab grown diamond:
- High Pressure, High Temperature (HPHT)
The High-Pressure High Temperature (HPHT) method produces diamonds in laboratories that mimic the high pressure, high temperature conditions of natural diamond formation in the earth. The HPHT diamond growth occurs as extreme pressure of 5–6 GPa (gigapascal, a measurement multiple of a unit of pressure) and high temperature of 1300–1600°C is applied to a seed of carbon. The seed acts as a guide for the lattice of carbon (that will soon become the diamond) to grow layer by layer within a matter of days until the desired carat weight is achieved.
Another use for this HPHT is to take lower-quality diamonds, whether natural or lab-grown, to improve color and clarity. Not only can this method make diamonds more colorless, this process can also be used to change the color of diamonds into pink, blue or yellow resulting in the diamond being considered a “treated” diamond.
- Chemical Vapor Deposition (CVD)
This is a newer technique which allows scientists to grow diamonds using lower temperatures (700°C to 1300°C) and lower pressures than the HPHT method utilizing a plasma reactor chamber. Carbon enriched gas is pumped into the vacuum chamber where microwaves are introduced to heat the gasses and generate plasma. As the temperature climbs over several thousand degrees, this plasma begins depositing onto a diamond seed and crystallizing creating the diamond layer by layer. The eventual size of the diamond depends on the time allowed for growth.
Are lab-grown diamonds real diamonds and how do you identify them?
In a succinct statement… Yes, they are real. Both lab-grown diamonds and natural diamonds have the same cubic crystalline form consisting of pure carbon. The difference between lab-grown diamonds and natural diamonds cannot be distinguished by the naked eye. Their identity can usually only be ascertained by gemological laboratories using specialized instruments which detect minor differences in the trace elements of a stone and its crystal formation to determine its origin; that being, natural or grown in a lab.
Additionally, just as a note, in addition to colorless stones, lab-grown diamonds are also available in a vast array of colors that are extremely rare and expensive in natural form and are considerably less expensive than natural diamonds of comparable size and quality. Plus, lab produced diamonds shine and sparkle just like natural diamonds.
What Is the Difference Between Lab-Grown and Simulated Diamonds?
To be blunt, simulated diamonds are not diamonds. Unlike lab-grown diamonds simulants are made from seed materials like glass or cubic zirconia having a similar appearance to diamonds. Additionally, simulants like moissanite lack the hardness and optical properties of lab-grown diamonds and as time increases, simulants do not hold up to the daily wear-and-tear of use and their sparkle diminishes.
How are Lab-Created Diamonds Graded and Certified?
Similarly, to natural diamonds, laboratory produced diamonds undergo the same rigorous grading process as natural diamonds at gemological grading facilities. Stones are graded for the same 4C’s that a natural stone undergoes. The difference is the report issued is for a laboratory-grown stone and stated as such in the identification of the stone evaluated. For protective measures for the consumer, gemological institutions like GIA also laser-inscribes the diamond’s girdle with a report number and a statement identifying the diamond as laboratory produced.
Because of price and availability of colors, lab-grown diamonds are now more in demand and becoming a popular alternative for many people. So, whether you are considering a lab-grown or natural diamond, we recommend that you always obtain a diamond report from one of the main gemological labs.
Hello,