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Diamond grading is the process to evaluate a diamond’s quality based on the 4C’s. The four C’s are carat, colour, clarity and cut. While the four c’s and diamond grading is comprehensive, it does not cover every aspect of a diamond's appearance or characteristics. In this article, we will explore what diamond grading doesn’t include such as phosphorescence, hues, internal strains and striations and why these factors can significantly impact the appearance of your diamond.   What is diamond grading?  Diamond grading is a standardised process of evaluating a diamond's quality. Organisations like the Gemological Institute of America (GIA) and International Gemological Institute (IGI) evaluate diamonds based on the 4C’s.  Cut: How well the diamond interacts with light from the arrangement and proportions of the diamond facets. Colour: The presence of colour, measured on a scale of D-Z Clarity: The number and size of internal and external blemishes and inclusions Carat: Unit of measurement to describe the diamond's weight, One carat is equal to 200 milligrams, or 0.2 grams. Diamonds are assigned a grade for each factor, which describes the overall quality and appearance of the diamond.  Why was diamond grading introduced?  Diamond grading was introduced to establish a standardised system for evaluating diamonds. Previously jewellers would describe their best diamonds by A, AA, AAA , numerals 1, 2, 3, roman numerals or a combination of both. This led to confusion between customers. Robert M Shipley established the 4C’s in 1931 to protect consumers and maintain a standard for evaluating gemstones. Robert also established the Gemological Institute of America (GIA) in 1931 and is known today as the leading source of knowledge, standards and education in gems and jewellery. Jewellers began using the 4C’s in 1941 to describe a diamond’s features.  What isn’t graded for?  The four C’s do not cover everything. Defects such as phosphorescence, strains, striations, bowties, and tints/hues of the diamond, are not detailed in the grading report. These factors significantly impact the look of the diamond but are outside the traditional grading framework and not openly discussed. This is why you can have two diamonds graded identically but look very different.  Why are lab diamonds being grown with these defects?  The demand for lab grown diamonds has increased but a significant portion are being produced with defects. Many of these defects are intentional due to trying to produce as many lab diamonds as possible, as fast as possible, for as cheap as possible. This has created two lab diamond markets, good quality lab diamonds and bad quality lab diamonds. The problem is, consumers are unaware and purchasing based directly off the report from ecommerce websites who do not hold the stock or inspect it in person. Manufacturers unable to get rid of their poor quality lab diamonds chuck these on a database and are being sold directly to consumers through ecommerce websites.  Diamonds with phosphorescence (glow under UV light) are caused by boron impurities. Less than 0.1% of naturally occurring diamonds contain boron impurities, they are considered rare. Grading did not need to account for this previously as it was extremely rare to come across.  Blue Tinge   HPHT diamonds aren’t grown in a vacuum like CVD, making it harder to control the environment they are grown in. Nitrogen from the atmosphere (78%) is impossible/very difficult to remove from the growth cell, causing the diamond to turn a golden brown/bright orange. To get a colourless diamond the nitrogen must be removed. The easiest solution is to add boron. However, boron does not adhere to the growth cell uniformly, to prevent the brown/orange hues from the nitrogen, boron must be overcompensated for. If too much boron is added, the diamond turns a blue tinge.  What is Phosphorescence  Phosphorescence diamonds continue to glow after being exposed to ultraviolet (UV) light. Phosphorescence differs from fluorescence, which is noted on a grading report. Fluorescent diamonds glow under UV light but stop glowing once the UV light source is removed.  Phosphorescent diamonds can remain glowing for seconds or minutes once the light source has been removed. Phosphorescence is typically found in Type IIB diamonds, which contain the trace element boron. Type IIB diamonds are exceptionally rare to find in naturally occurring diamonds, less than 0.1%.  What causes Phosphorescent diamonds? Phosphorescence in diamonds is caused by the presence of Boron. Boron is introduced to counteract the unwanted effects of nitrogen. Nitrogen is naturally present in the atmosphere, so it can be found in the diamond growth cell, or it can be deliberately added to speed up the diamond growing process (usually by 200-300%).  Boron is used to neutralise nitrogen. Boron does not uniformly adhere to the crystal so it must be overcompensated for. Too much can cause the diamond to turn a blue tinge/hue. The phosphorescent glow may not be even throughout the diamond because the boron does not uniformly adhere.  Type IIB diamonds are more likely to have a blue tinge however, not all Type IIb diamonds will have a blue tinge or phosphorescent glow. Some diamonds without a blue tinge will have a phosphorescent glow. This must be tested in person, there is no way to tell from photos or videos and it is not mentioned in the grading report.  Phosphorescent diamonds are not known to have any impact on the diamond’s quality or appearance in normal lighting conditions (some fluorescent light bulbs can set off the phosphorescent glow) however, it’s important to be aware of this trait if it’s something you prefer to avoid. If you like the look of this and want a diamond that glows, and think it’s unique and cool then this can be sourced, as long as you are aware of what you are purchasing. Why is phosphorescent diamonds an issue?  Diamonds are electrical insulators and moissanite is an electrical conductor. Due to trace elements, different electrical properties can be given off. A diamond containing boron can give the result of synthetic moissanite on basic diamond testers. Synthetic moissanite can also test as diamonds as it has been refined over time to have lower electrical conductivity.  What are blue/grey/brown Tinges/Hues in lab diamonds? - colour grading Colour grading assesses the presence of colour in diamonds when viewed from the culet-up. Diamonds are thought to be colourless (D) to yellow/brown (Z). However, with lab grown diamonds and the presence of trace elements, it’s important to note that the D-Z scale includes tinges, not just colourless, yellow and brown. Diamonds beyond the Z range are classified as fancy colour diamonds, which display notable colour when viewed face up.  A diamond with a D colour grading can look brown face up because of vacancies in the atomic structure. As the light reflects through the diamond, the atomic vacancies can cause the diamond to look brown. A diamond can look different face up vs culet up. It is nearly impossible to detect grey hues/tones in a 360 video.  How do these brown/grey defects occur? Manufacturers are incentivised to run the machines faster, add agents that speed up the growth, reuse cheap materials and grow as many diamonds as possible for as cheap as possible to maximise profits. This creates ugly lab diamonds. To undo some of these side effects, other elements and treatments are added, which come at a cost and produce these brown/grey/blue defects. To produce better lab diamonds, manufacturers would need to run the machines slower, source better quality seeds and materials which would come at a higher cost and not add agents that speed up the growth; however, this would affect profits and it’s easier and cheaper to grow the diamonds fast and then add treatments later on.  What are some ways blues/greys/browns can occur? Nitrogen: Accelerates the growth of diamonds by 200-300%, causes yellow, orange  or brown tints Boron: Added to counteract the nitrogen, too much causes a blue tinge. Boron must be overcompensated as it does not uniformly adhere to the growth cell. Irradiation: Fixing a blue tinge HPHT diamond with irradiation can cause it to turn grey Running the machine too hot and fast: Can cause atomic-level voids, giving the diamond a brown appearance Graphite nano-clusters: Causes the diamond to appear grey. Can occur from post growth treating a CVD diamond, carbon atoms revert back to graphite bonds.  Metal Inclusions: Adding aluminium and titanium agents can cause metal inclusions, making the diamond appear grey Pinkish brown: Nitrogen beside a vacancy/void in the crystal structure Impacts of these defects: Two diamonds with the same grade can look extremely different, with one appearing dull or grey.  Currently there are two lab diamond markets, good quality labs and bad quality labs. Manufacturers are struggling to get rid of the bad quality labs, which are often heavily discounted and listed on databases connected to retail websites. These diamonds are typically showcased with 360-degree videos and photos, but the quality and consistency of these visuals depend on the seller. It’s nearly impossible to judge a diamond’s true quality from these images/videos and grading reports do not report on defects such as bowties, phosphorescence, blue/grey/brown tints, strains and striations, leading to situations where consumers may unknowingly purchase lower-quality stones at seemingly “great prices.” CVD Strains and striations:  Strain:  Looks like streaks of glass or blurriness. Strain is caused by using poor quality seeds. The carbon atoms do not evenly deposit onto the seed, causing the crystal lattice structure to deform, since the crystal lattice structure is not even, it affects how the light performs, causing birefringence, the light to scatter. HPHT treatment can improve strain.  Strain is not mentioned on a grading report.  Striation: Diamonds with striation appear out of focus and dull. Striation looks like visible parallel lines or growth lines. Striation can occur from minor disruptions in diamond formation or from stopping and starting CVD reactors. CVD reactors have a viewport, so if manufacturers notice the diamond is not growing quite right, they can stop the reactor, make adjustments, then start the reactor again. However, the conditions and concentration of elements are at different levels and not consistent when you stop and start the reactor, causing striation.  All CVD diamonds have some level of striation, but it varies in levels of intensity, the more the CVD reactor is stopped and started, the worse the striation and the increased chance of the carbon atoms depositing incorrectly, worsening the look of the diamond.  Striation is not mentioned on a grading report, a diamond may be given a VVS1 grading but still have striation.  Bow Tie Bow ties are dark connected triangles at the centre of elongated diamonds, they look like a bow tie. Bow ties are not mentioned on grading reports, you will need to examine the diamond in person to identify the strength of the bowtie. Bowties are common in elongated shapes but range in intensity. Bow ties can be caused by poor cut and symmetry.  Windowing Windowing is when an area of the diamond is not returning light to the eye. Some facets rather than reflecting the light back, act as a window, allowing it to pass through. Step diamonds such as emerald tend to show windowing more than other shapes due to their large facets.  Diamond grading does not mention whether a diamond has windowing or to what degree, this must be inspected in person.  Why are these lab diamond defects a problem?  Jewellers aren’t aware of the defects common in lab diamonds. Reasons being, these issues aren’t graded for (which is not a valid excuse), they don’t know and haven’t been educated (not a good excuse). Businesses are making a larger margin on these cheaper lab diamonds by selling them among the nice ones, it’s like the lemon and the car yard dilemma. Jewellers aren’t curating and testing their own list of trusted suppliers, they aren’t inspecting every diamond in person and sending back the rejects. They are reliant on a database that can be connected to their website, also reducing the cost needed to invest in stock and curing their own list of suppliers. This leaves the choice and responsibility in the hands of the consumer who can’t avoid these issues or doesn’t know what to look out for, even if they wanted to look out for it, it’s not graded on, and a lot of these problems can only be discovered from inspecting the diamond in person. In house grading:  Another issue facing the diamond industry is ‘in house grading’. Some lab grown diamond companies no longer need to send their stones to an IGI office for grading. IGI India has established laboratory setups inside the factories of high volume diamond growers. It’s not unusual for labs to do grading on site however, ‘in factory’ operations could create the appearance of a bias.  “While we conduct quality checks and periodic calibration of our gemologists to reassess and adjust their grading techniques, such measures may not be effective in preventing all instances of grading errors or fraud by gemologists or third parties.” - Source  Why are consumers led to believe lab diamonds are inferior?  Some buyers believe lab diamonds are inferior and don’t sparkle as nicely as natural diamonds. Since the defects have become more noticeable and prominent in cheap lab diamonds, even non gem experts are able to see them, leading to this view. Jewellers will also tell consumers lab diamonds are inferior because they are either not informed on the defects and influence this has on the appearance or they want to try and persuade consumers to purchase a natural diamond.  With poor lab diamonds flooding the market, suppliers are struggling to get rid of them, they are being priced extremely low to free up capital as growing diamonds uses a huge amount of energy, people, machinery and resources. Some businesses are passing on the savings, while others are charging premium prices for poor quality lab diamonds. Consumers are questioning why there might be a 3-5x price difference and since the defects are not graded on, those not aware are not able to differentiate and are led to believe they are getting a ‘good deal’ on these cheaper defective lab diamonds, or these high-quality lab diamonds that are priced higher are not worth the price.  There is a current gap in knowledge, the problem is only going to get worse until consumers are more educated and demand better quality lab diamonds. Until then, it's the wild west trying to buy a good quality lab diamond online.  Diamond grading is essential for evaluating a diamond's quality, but it has limits, especially when it comes to lab diamonds. Grading has not been updated to reflect the defects and variances between lab diamonds. Characteristics like phosphorescence, grey/blue/brown tints and hues, strains, striations and bow ties are not included in grading reports, making it a gamble for the consumer to select a diamond online. It’s essential when choosing a diamond or engagement ring to choose a trusted jeweller (such as Henry Francis) who is knowledgeable, able to explain the nuances, what to look out for and is inspecting their diamonds in person before passing the choice onto the consumer. 

Understanding the distinction between lab-grown diamonds and natural diamonds is crucial to making an informed decision. In this article, we will explore the differences, similarities, and important factors to consider by examining their chemical, physical, structural properties along with the environmental and sustainable impacts.  What is a diamond:  According to the Federal Trade Commission (FTC), the definition of a diamond is “a mineral consisting essentially of pure carbon crystallised in the isometric system”.  Previously, the FTC defined a diamond as a “natural” mineral; this word has been removed from the FTC’s definition of a diamond. The FTC has also recommended the word “synthetic” is not an accurate descriptor, this is because lab grown diamonds are not synthesised. Lab grown diamonds are grown by combining carbon atoms in a crystal lattice, just as they are created in nature.  What is a lab diamond? Lab grown diamond refers to a diamond created in a laboratory made from pure carbon, arranged in a crystal structure known as an isometric system. Lab diamonds are produced by either High Pressure High Temperature (HPHT) or Chemical Vapour Deposition (CVD).  What is a naturally formed diamond? A naturally formed diamond is a gemstone made of pure carbon created in the earth over hundreds of years from high pressure and temperature. Naturally formed diamonds can be found in a range of places and countries, such as kimberlites, alluvial deposits and Russia, Australia, Botswana, South Africa etc.  What is the chemical composition of a lab and natural diamond? Both lab-grown and natural diamonds are made of pure carbon, arranged in an isometric crystal structure, making them the hardest naturally occurring substance known. The chemical composition of natural and lab diamonds is the same. Diamonds are typically 99.95% carbon with the other 0.05% made up from trace elements. Both lab and natural diamonds possess the same mohs rating of 10. Mohs is the measure of hardness determined by its resistance to scratching.  Both lab-grown and natural diamonds are graded to the same standards and criteria, ensuring consumers can assess quality based on an objective criteria. There are however characteristics present in lab diamonds from poor manufacturing such as blues/greys/browns/phosphorescence that are not graded on which influences how the diamond will look. To read more How to tell the difference between a lab diamond and a natural?  Lab-grown diamonds have a range of ‘markers’ that identify it as having been created in a lab. For example, HPHT lab grown diamonds grow in a cuboctahedron shape and have 14 growth directions, CVD lab grown diamonds have a cubic shape and only grow in one direction. Naturally formed diamonds have 8 growth directions.  HPHT diamonds tend to have colour zoning/uneven colour distribution due to how the elements concentrate as the crystal forms.  CVD diamonds tend to have striations which look like visible parallel lines or growth lines, the intensity and depends on the way the diamond has been grown.  All diamonds that have been graded will be laser inscribed along their girdle with information as to whether they are a lab grown diamond or naturally formed diamond. Allowing anyone to look up the certification number and check the report. Most jewellers cannot distinguish a lab diamond from a mined diamond without specialized equipment.  Because of the ‘markers’ if diamond manufacturers were to falsely inscribe a lab diamond with a natural diamond number, it would be able to be identified.  Lab-grown diamond cost vs natural  Lab diamonds cost less than natural diamonds. This is because lab diamonds do not have a supply restriction and can be manufactured in a matter of weeks. Natural diamonds however, must be mined from the earth in a variety of ways. This takes huge capital investment and de beers has been able to manage a monopoly supply on natural diamonds, dictating the price.  Energy/sustainability of lab-grown diamonds vs natural Natural diamonds require huge energy, resources and capital investment to mine. Natural diamonds must be mined and sorted by machines and people. There are a range of economic and environmental benefits and impacts that we do not have access to the current and unbiased information to accurately and fairly argue these points, however, as a consumer, these are some things you may want to consider.  Some of the following arguments made: Natural diamond provide jobs and help build the economy and wealth of those around the mines, providing opportunity they otherwise wouldn’t have  Natural diamonds exploit vulnerable people, there is a lack of healthy and safety negatively affecting those working in the mines Natural diamond mining damages the environment from contaminating soil, carbon emissions, deforestation, water contamination and more. Leaving those economically worse off Supporting ethical natural mining benefits communities, economies and people If there is still demand for natural diamonds, unethical practices will continue There has been many claims and research made available stating lab diamonds are sustainable, clean, green and what you should choose to do your bit for the environment however, these claims are irresponsible and fail to consider the following: The waste management of the factory How the factory is generating the huge amounts of power required - usually from coal/oil Growing lab diamonds requires metals and elements that are mined for (CVD growing uses methane which is typically sourced from mining fossil fuels) Entire supply chain Lab diamonds don’t have the same economic benefit to communities, but is this offset by the environmental damage caused by natural diamond mining?  Did the emissions research consider diamond type, size and machine used? The different reactors have different energy efficiencies, also the larger the carat the more energy required There is little publicly available data The publicly available data misrepresents/ construes the data for example: CO2 data on lab diamonds typically only includes the production of the diamond in either a CVD or HPHT reactor, it fails to include the CO2 output on cutting, polishing, manufacturing into jewellery, shipping, the entire end to end process.  It’s irresponsible to report only on the information and data that supports a certain agenda or so that a business can be perceived as “clean and green”. It’s also unethical to influence purchasing decisions without accurately representing the entire argument.  Generic comparisons between natural and lab diamonds can not be made in terms of energy and sustainability without more publicly available data that has not been funded by influencing agendas.  Common misconceptions between natural and lab diamonds  Jewellers have been known to market “natural diamonds will hold their value better than lab diamonds”. This is incorrect, whether it’s a lab-grown diamond or a natural diamond, they do not hold their resale value. If you’re purchasing a diamond for its resale value, you might want to consider a different type of investment. A diamond is purchased with the intent to never sell, but to eventually pass on to family as an heirloom.  Lab diamonds are flawless:  No, lab diamonds are not flawless, with the increase in demand, we have seen cost cutting measures and shortcuts in the way lab diamonds have been manufactured. Defective, poor-quality lab diamonds have entered the market. Near perfect diamonds can be created, it is possible, but manufacturers are incentivised to produce more, faster, cheaper and instead use other elements and methods to help mitigate the side effects of rushing the process. It’s essential your jeweller is inspecting your diamond in person as a lot of these defects are not reported on in the grading report.  How to choose between lab and natural  Choosing between a lab and natural diamond is up to you, it is entirely dependent on what you prefer. To help make this decision, you can ask yourself the following questions What’s important to you?  Do you prefer a natural diamond? Or a lab diamond?  Do you want a larger carat or smaller carat? Do you want a higher clarity and colour?  What is your budget? At Henry Francis, we believe the choice is yours, nobody should influence or take the decision from you. There is no right or wrong answer, it’s what you prefer. 

The Four C’s, cut, colour, clarity, and carat are the universal standard for evaluating a diamond. Established by Robert M Shipley, founder of the Gemological Institute of America (GIA), this system ensures consistency and accuracy in diamond grading, allowing consumers to make informed purchasing decisions.  Why was the four c’s developed:  Robert M Shipley established GIA, Gemological Institute of America in 1931 to provide formal gemological training to jewellers. The Four C’s were developed by Shipley to act as a universal scale to evaluate the characteristics of diamonds. Before the Four C’s, jewellers used a variety of terms such as A, AA, AAA, or the terms “without flaws” or “without imperfections”. These inconsistent descriptions made it difficult for consumers to compare diamonds and for jewels to communicate quality effectively.  As GIA states, without strict standards, the characteristics, quality, and value of a diamond would be left open to interpretation.  Carat:  Carat refers to the weight of the diamond, not the size. One carat is equal to 0.2 grams or 200 milligrams. Diamonds are measured to a hundredth of a carat for precision. While carat weight is a key factor in determining a diamond’s price, it does not directly tell you how large or visually impactful the diamond will appear. The weight of the diamond is one element in its overall appearance.  Carat vs perceived size:  The way the diamond has been cut influences how large the diamond appears. A well cut diamond will reflect light more efficiently and appear bigger, even with a smaller carat weight. Shape also affects how carat weight is distributed across the diamond’s surface. Certain shapes like oval or pear tend to appear larger than other shapes of the same carat weight because they have a larger surface area to depth ratio. This means between two diamonds that have the same carat weight, one may appear bigger, depending on how the weight is spread across the stone.  Cut:  Cut refers to how well the diamond interacts with light, influencing its brilliance and sparkle. Only round brilliant diamonds can be assigned a cut grading, this is because they have a standardised facet pattern that allows for consistent evaluation of how well light interacts with the stone. According to GIA’s standardised cut grading system, diamonds are evaluated on a 10-point scale ranging from Poor to Ideal, taking into account the following:  Components of a diamonds cut: Brightness: The total light reflected from a diamond  Fire: The dispersion of light into the colours of the spectrum  Scintillation: The pattern of light and dark areas and the flashes of light, or sparkle, when a diamond is moved.  Weight ratio: How efficiently the diamond’s weight is distributed to maintain it’s proportions  Durability: Resistance to damage based on its proportions and design (a thin culet can lead to easy damage and breaking) Polish: The smoothness of the diamond’s surface, including scratches, nicks and chips.  Symmetry: Alignment and shape of a diamond’s facets.  IGI grades cut from fair to ideal.  Why does cut matter:  If a diamond’s cut is too shallow, deep or out of proportion, light can leak out of the lower facets of the stone instead of reflecting back to the viewer. This results in reduced sparkle and brilliance, making the diamond appear dull or lifeless.  A common misunderstanding is confusing cut with the shape of the diamond. For example, people will refer to an “oval cut” diamond, but this is incorrect. Oval is the shape, as the cut refers to the quality of the diamond’s proportions, symmetry, and polish, not its shape.  How to evaluate diamonds not given a cut grading? For fancy shaped diamonds (all other diamond shapes that are not round brilliant), we look at the table and depth percentage. These measurements reveal how well the diamond has been cut in terms of its proportions, the ratio to its height and width. This influences the diamond's brilliance and sparkle by determining how the light interacts with the stone.  Colour:  Colour refers to the absence of visible colour in a diamond, with the grading scale measuring from D colours to Z. The clearer and more colourless the stone is, the more valuable, rare, and expensive the diamond is going to be. Diamonds beyond the Z range are classified as fancy colour diamonds. Diamonds are measured on colour from the culet up. Robert M Shipley, began the colour grading scale at D to avoid association with the old methods of colour grading.  Colour is measured in a 10 point scale:  D - F: Colourless (0.0 - 1.0) Highest grade, diamonds will appear to have no colour in any setting. Diamonds without colour are extremely rare.  G - J: Near colourless (1.5 - 3.0)  These diamonds have little colour When mounted in jewellery these diamonds will appear colourless K - M: Faint (3.5 - 4.5)  These diamonds have visible colour.  Smaller diamonds less than 0.5 carat may appear colourless or near colourless when in jewellery.  N - R: Very Light (5.0 - 7.0) Noticeable colour that becomes more apparent when set in jewellery S - Z: Light (7.5 - 10) Visible hue or tone  Fancy colour diamonds These fall outside the D-Z category, fancy colour diamonds are colours beyond the Z range which display notable colour when viewed face up. These diamonds show colours such as blues, pinks, greens and more, caused by specific trace elements or structural anomalies. Unlike colourless diamonds, where less colour is more valuable, the value of fancy colour diamonds increases with the intensity and purity of their colour.  Assessing diamond colour from online photos and 360 degree videos It’s impossible to accurately determine a diamond’s colour or detect subtle undertones, such as grey, brown or blue, without examining the diamond in person. While 360-degree videos and photos on diamond websites can provide a sense of choosing your diamond, they are highly inaccurate and fail to reveal the details.  This is a diamond we ordered from a large popular ecommerce website. This is the video that was displayed. This is the diamond that arrived How is colour measured:  Diamond colour is done under controlled lighting conditions using a set of master stones as benchmarks. Colourless diamonds are extremely rare in nature. Colourless diamonds allow more light to pass through, enhancing their brilliance and sparkle. Even subtle hints of colour can affect how light reflects and refracts within the diamond.  How are diamond colour, size, shape and setting related? Size: The colour of a diamond is more noticeable in larger stones. As the size of the diamond increases, the table becomes larger, making any visible colour more apparent.  Shape: Diamond shape also impacts how colour appears. Stones with larger facets, like emeralds, ovals or radiant cuts can display more visible colour than shapes with smaller facets, like the round brilliant.  Setting: The metal in the ring setting can impact the appearance of the diamond’s colour. A diamond with a faint colour (K-M) may appear more colourless when set in white gold or platinum, as these metals compliment its tone. Compared to set in yellow gold, the warmth of the metal can accentuate the diamond's colour, making any hue more noticeable.  Clarity:  Clarity assesses the presence of inclusions (internal flaws) and blemishes (surface flaws), the fewer imperfections, the higher the clarity grade. According to GIA, “diamonds are assigned clarity grades ranging from Flawless (FL) to diamond with obvious inclusions (I3)”. The grade is based on the number, size and location of the inclusions and blemishes.  Evaluating diamond clarity requires 10x magnification to detect even the smallest imperfections that may not be visible to the naked eye. Different diamond shapes can affect how different clarity gradings look. For example, round brilliants can sometimes hide minor inclusions, compared to an Emerald where inclusions with the same clarity grading may be more noticeable due to the open facets.  Clarity Grading:  Flawless:  No internal or external characteristics Less than 1% of all diamonds are FL clarity Internally flawless: Some small surface blemishes may be visible under microscope on IF diamonds  IF diamonds have no inclusions within the stone, only on the surface Visually eye clean Very Very slightly included:  Minuscule inclusions that are difficult even for trained professionals to see under 10x magnification Eye clean appearance: Very slightly included:  Minor inclusions ranging from difficult to easy to see under 10x magnification Slightly included diamonds: Inclusions are noticeable under 10x magnification Detectable by the eye Included diamonds:  Obvious inclusions  Visible by the eye  Henry Francis does not sell Included diamonds Types of Inclusions:  Bruise: Damaged diamond from impact that causes root like lines on the inside of the diamond. Bruises can affect the structural integrity of the diamond  Chip: A small, shallow opening on the surface of a diamond often found near the girdle, culet or facet junctions. Cavity: A large or deep opening in the diamond's surface Knot: Cluster of diamond material that extends from the diamonds interior to the surface Graining: Irregularities in a diamonds crystal lattice structure Feather: Internal fractures, looks like a feather Crystal: A mineral crystal contained in the diamond. Pinpoint: Shiny or microscopic crystals within the diamond Cloud: Numerous pinpoint inclusions that may be too small to be distinguished individually and give it a cloudy, hazy appearance Needle: A thin crystal that looks like a tiny needle  Twining Wisp: Complex, they form when multiple crystal growth directions intersect within a diamond.  Indented Natural: Occur when the rough diamond's natural surface is not entirely removed during the cutting and polishing process. These inclusions may appear as depressions or rough patches on the diamond's surface Internal Laser Drilling: Laser drilling within a diamond that creates a surface-reaching feather. This then provides access for bleaching to decrease the visibility of inclusions  Bearded Girdle: occurs when improper bruting (which is cutting a diamond to make the girdle round) which cause hair-like inclusions to form across the diamond's girdle area  Laser Drill-hole: A tiny, surface-reaching tunnel produced by a laser light beam. Types of Blemishes:  Abrasion: Minute nicks along the facet junctions of a diamond, giving it a fuzzy appearance  Extra facet: A facet that's not required by that diamond shape Lizard Skin: Wavy or bump area on the surface of the polished diamond Natural: Portion of natural rough diamond left on a fashioned stone  Nick: Small notch  Pit: Small opening that looks like a tiny white dot  Polish: Parallel grooves and ridges left by polishing  Burn Mark: Hazy surface that results from excessive heat during polishing  Rough Girdle: irregular or granular girdle surface  Scratch: A thin, dull white line across the diamonds surface  Surface graining: Graining on the surface  How Inclusions form:  Inclusions and blemishes occur during the formation of a diamond.  Causes of inclusions in natural diamonds:  Trapped minerals Internal stress Growth patterns Natural radiation Causes of inclusions in lab diamonds:  Imperfect seeds Trapped gasses or metals Added trace elements Growth irregularities Post-growth treatment Temperature changes Diamond Treatments: Enhancing Appearance and Colour: Diamonds can undergo treatments to improve their appearance, clarity or colour. There are two types of treatment: Permanent and Non-Permanent. GIA does not grade diamonds with non-permanent treatments as their effects are not stable and long-lasting. For diamonds with permanent treatments, GIA will disclose in their report the treatment type.  Permanent treatments are lasting and do not typically affect the diamond's structure. Examples include laser drilling, HPHT and irradiation.  Non-Permanent treatments are temporary and may require maintenance or can degrade over time. Examples include fracture filling and coatings.  What is the 5th C? The 5th C refers to confidence or “certification”. Certification from a trusted 3rd party such as IGI or GIA gives you peace of mind and assurance of the diamonds quality. At Henry Francis we only sell IGI or GIA certified diamonds.  It’s important to note that while the Four Cs provide valuable insights into a diamond’s quality, they do not independently determine the diamond’s price or act as a certification. A diamond’s value is influenced by a combination of factors, including market demand and the interplay of its unique characteristics. The Four C’s provide a standardised framework for assessing diamonds, but they don’t account for every aspect that can affect a diamond’s appearance. Is it better to have a bigger diamond or a better quality  When deciding between a larger diamond and one with better quality, it depends on personal preference and priorities. A larger diamond may appear more impressive due to its size, but a smaller diamond with better cut and quality can often appear more brilliant and sparkly, offering more visual appeal. If you're unsure what you are after, please reach out to us at Henry Francis for help.  What does VVS mean for diamonds VVS (Very Very Slightly Included) diamonds have inclusions that are so tiny they are difficult to see even under magnification. These diamonds are considered excellent in terms of clarity. What's more important, colour or clarity Both colour and clarity are essential factors in diamond grading, but their importance depends on individual preference. Colour affects the diamond’s visual appeal, with colourless diamonds being the more valuable, while clarity impacts the internal perfection of the diamond. In some cases, a diamond with a slightly lower clarity but better colour may be more desirable. 

Lab grown diamonds are diamonds, primarily constructed of carbon atoms in a crystallised lattice structure, made in a lab/controlled environment. Lab diamonds are chemically, physically and optically identical to mined diamonds. There are two primary methods of creating lab diamonds: Chemical Vapour Deposition (CVD) and High Pressure High Temperature (HPHT). In this article we will address the differences, pros and cons and which produces the better lab diamond.  How are HPHT diamonds grown? High Pressure, High Temperature replicates the natural conditions of diamonds formed deep within the earth by subjecting carbon to extreme temperature and pressure.  HPHT diamonds are grown by placing a seed inside an insulated growth cell, which is then placed at the centre of a hydraulic press and subject to extreme pressure and temperature, typically around 2000 degrees celsius and 1 million psi. Carbon, in the form of graphite, melts under these conditions and atom by atom crystallizes onto the diamond seed. The time it takes for the diamond to grow depends on the desired size and quality.  HPHT diamonds grow in a both octahedral and cubic shape, with growth occurring in 14 directions.  How are CVD diamonds grown? CVD diamonds are grown by placing a lab diamond seed into the reactor, gas is removed and hydrocarbon is added. Microwave energy breaks apart the hydrocarbon molecules. Atom by atom, the crystal structure grows vertically in the shape of a cube. CVD diamonds have one growth direction.  The number of diamonds grown depends on how large the CVD reactor is and how many diamond seeds are placed inside.  CVD Vs HPHT - what are the differences: 1. Colour: HPHT diamonds can come in a range of colours from near colourless, blue, brown or yellow hues depending on the trace elements used during growth.  CVD diamonds tend to come out with a brown/grey hue which can be post growth treated with HPHT to make them colourless.  In some cases, post growth treating a brown CVD diamond can make it appear worse.  2. Control Over the Process HPHT: Once growth starts, the HPHT press is usually not stopped. Manufacturers rely on precise calculations and formulas, as the process cannot be visually monitored.  CVD: The reactors have a viewport, allowing manufacturers to monitor the growth. This provides greater control but stopping and restarting the process can introduce defects due to the changing conditions. 3. Colour distribution/zoning:  HPHT diamonds can display geometric colour zoning which is an uneven distribution of colour throughout the diamond. This is caused by the elements concentrating at different levels while the diamond formed.  Naturally formed diamonds can also have colour zoning but it will not contain a geometric pattern like HPHT diamonds.  CVD diamonds tend to have an even colour distribution because the gasses (hydrogen and methane) spread evenly during the diamond formation.  4. Fluorescence:  Both HPHT and CVD diamonds can exhibit fluorescence, which causes them to glow when exposed to UV (ultra violet) light and stop glowing once this light source is removed.  Fluorescence is mentioned in the grading report.  Phosphorescence, when the diamond continues to glow for seconds or even minutes after the light source has been removed, is unique to some HPHT diamonds due to boron impurities and is not mentioned in grading reports.  5. CVD Vs HPHT Cost:  CVD diamonds cost less to produce than HPHT diamonds. CVD diamonds require smaller equipment, versus HPHT which requires large reactors weighing 70 tonnes each.  HPHT can't grow as many diamonds compared to CVD so it has a lower production efficiency 6. Inclusions:  Both CVD and HPHT diamonds can contain inclusions, these inclusions can vary in size and type, various factors influence these. HPHT diamonds may contain metallic inclusions, due to metals used during the growth entering the diamond. If the metallic inclusions are large enough, the diamond can be picked up by magnets.  CVD diamonds do not develop metallic inclusions, instead they can develop dark pinpoint inclusions, such as graphite inclusions.  7. Strain:  CVD diamonds display strain patterns, the intensity varies. HPHT diamonds tend to not have strain patterns because the pressure applied during growth is even, if they do, they are very minor.  8. Passing a diamond tester: Diamonds are thermal conductors and electrical insulators.  Old basic diamond testers used to test for thermal conductivity, how quickly heat travels through the stone. However, with moissanite entering the market, which is also a great thermal conductor (not as good as diamonds), moissanite was passing basic diamond testers. Diamond testers have had to evolve to test for thermal and electrical conductivity.  Due to trace elements, diamonds can have different electrical properties to what is typical, boron if concentrated enough, can have a notable effect on the electrical conductivity of a diamond. giving off the results of synthetic moissanite.  Synthetic moissanite can also test as diamonds as it has been refined over time to have lower electrical conductivity.  CVD Vs HPHT: What to look out for: When shopping for lab-grown diamonds, it’s important to know what to look out for in each type: CVD: Greys, Browns, Strains and Striations HPHT: Blues, Browns, Phosphorescence CVD vs HPHT which is better?  There is no definitive answer to which method is superior. Both CVD and HPHT have their strengths and weaknesses. While both methods can produce stunning, high-quality diamonds, they can also yield lower-quality stones if poor materials or growth catalysts are used.