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Understanding Various Varieties of Diamonds

Lab-grown vs natural diamonds What are Lab-grown diamonds? Lab-grown diamonds, also commonly known as engineered diamonds or cultured diamonds, are created in a controlled laboratory environment. Unlike natural diamonds that form over billions of years deep within the Earth's mantle under extreme pressure and heat, lab-grown diamonds are produced in a much shorter timeframe using sophisticated growth methods that mimic the natural process. The creation of lab-grown diamonds typically starts with a tiny diamond "seed" that serves as the foundation for the new gemstone. This seed is then grown using either High Pressure, High Temperature (HPHT) or Chemical Vapor Deposition (CVD) processes, which replicate the intense conditions found deep within the Earth. How do lab-grown diamonds compare to natural diamonds? Physically, optically, and chemically, lab-grown diamonds are virtually identical to their natural counterparts. Even trained experts using sophisticated instruments can have a hard time telling them apart. The only real difference is the way they are formed. While natural diamonds take billions of years to develop, lab-grown diamonds can be produced in a matter of days. This faster growth process, however, comes at a cost. Lab-grown diamonds are not considered a sustainable or eco-friendly option. The production of these diamonds requires enormous amounts of energy, often from fossil fuels, making it difficult to label them as "green" or "environmentally friendly." The pros and cons of lab-grown diamonds The main advantage of lab-grown diamonds is their affordability. Because they can be produced more quickly and efficiently than natural diamonds, lab-grown stones typically cost less. This makes them a more accessible option for those on a budget. On the other hand, some consumers may be hesitant to purchase lab-grown diamonds, as they are not seen as a truly "natural" product. Additionally, the environmental impact of their production is a concern for those looking to make more sustainable choices. Additionally, a natural diamond retains its value, unlike a lab-grown diamond which loses its value. Natural fancy colored diamonds vs. treated diamonds Natural fancy colored diamonds are viewed as more desirable. Fancy colored diamonds are extremely rare in nature. They make up only 0.01% of all diamonds mined in the world. Some colors are more common than others. Hence, some fancy diamond colors are 1 in a million. The rarity of the color translates to the price of the diamond. Treated diamonds, on the other hand, are chemically treated to enhance their color. Scientists can change a diamond's color by employing one of the three processes: irradiation, HPHT (high pressure, High Temperature) or Coating. The Pros and Cons of Color Enhancement Methods Irradiation is a method that exposes the diamond to a large amount of energy to transform the diamond's structure to change or enhance the diamond's color. However, irradiated diamonds can be sensitive to heat and jewelry repairs, recutting, and repolishing can change their colors. HPHT archives the color by applying both high pressure and high temperature to a diamond to either create or enhance its color. Lately, coating is achieved by applying a silica coating to polished colorless diamonds to produce the desired fancy colors. The coating is not permanent; coated diamonds are susceptible to wear and tear. The coated diamond can be damaged by heat and chemicals during jewelry repairs and polishing. Science behind fancy colored diamonds Diamonds are the result of crystallized carbon. But, there are other elements that are part of the diamond's natural structure, and these factors influence the color grade of fancy colored diamonds. Diamonds are separated into two main groups; type I group and type II group. About 98% of all natural diamonds are a part of the type I group, characterised by the presence of nitrogen atoms within their structure. While colorless diamonds in this group retain elements of nitrogen, the nitrogen within these diamonds are not "light absorbing." But the nitrogen in fancy colored diamonds does absorb color, and this difference makes them appear orange and yellow. Low wavelength nitrogen absorption causes the diamond to appear yellow, higher nitrogen absorption causes the color to appear orange and brown diamonds are also influenced by nitrogen and other additional absorption-causing defects within the crystal lattice. The second group of diamonds, the type II group are the rarest diamonds. These diamonds are almost entirely nitrogen free, and make up only 2% of all diamonds. This group is further divided into IIa and IIb diamonds. Type IIa diamonds are the purest form of diamonds in nature and are made almost purely out of carbon. These diamonds appear colorless, brown or pink. Type IIb diamonds, which are extremely rare and become natural fancy blue or gray diamonds. These diamonds contain boron atoms in their composition, as a result the boron atom is responsible for the blue color in fancy color blue diamonds.

Discovering the Source of Diamonds

Diamonds are the result of crystallized carbon formed under extreme pressure and heat, conditions that are only found deep beneath the Earth's surface (150 to 200 kilometres underground). It takes anywhere from 990 million to 4.25 billion years to create a diamond. There are two ways of extracting diamonds. The first, is by volcanic eruption, which pushes the diamond from the depths of the earth to the surface. The second, and more common way, is mining. The Diverse Methods of Diamond Mining On average, miners have to move 250 tons of earth to find a single carat of diamond. There are multiple methods to mine diamonds. Open-pit mining is a method that requires miners to dig large holes, sometimes hundreds of meters deep. This removes many layers of soil and rock that have built up over millions of years, allowing minors to find the diamonds. Underground mining is more expensive compared to open-pit mining. This method is used when an open-pit mine is empty or when diamonds are too deep to reach with an open pit. Alluvial mining happens in riverbeds or along coastlines, where miners redirect water to reach diamond-rich deposits. By changing the water's path, they can uncover and extract diamonds. Lastly, marine mining uses large ships with special equipment to remove sediment from the ocean floor. The sediment is sorted on the ship, where diamonds are taken out and the rest is put back into the ocean. Want to learn more about diamonds? Book a free tour in our diamond polishing factory in Amsterdam. The most important diamond mines The Jwaneng and Orapa diamond mines in Botswana are among the largest and most valuable in the world. Jwaneng is known as the richest diamond mine based on value, producing millions of carats of diamonds annually. Orapa, the largest diamond mine in the world by area, is an open-pit mine that gives a substantial amount of diamonds each year. In Russia, Udachny and Mir are prominent mines, with Udachny being one of the largest in the country and the world. and Mir, despite the closure of its large open pit, still active underground. The Venetia mine in South Africa is the largest in the country and significantly contributes to national diamond production. Argyle in Australia, known for its pink diamonds, was one of the most productive mines until its closure in 2020. In Angola, the Catoca mine, one of the largest kimberlite mines in the world, produces a large volume of diamonds. Finally, the Karowe mine in Botswana is renowned for discovering some of the largest and most valuable rough diamonds in recent years. Despite the economic significance and impressive scale of operations in diamond mines, the diamond industry has a darker side. While these renowned mines contribute greatly to the global diamond supply and support local economies, there exists a parallel story of diamonds that fund conflict and human suffering. This brings us to the issue of blood diamonds, also known as conflict diamonds. The history of Blood Diamonds Blood diamonds, also known as conflict diamonds, are diamonds that were mined in areas of conflict and war. Civilians in these regions are often forced to work in horrible conditions, facing torture and exploitation. The term "blood diamonds" was made up by the United Nations to describe the negative consequences of the diamond trade in certain areas. These diamonds are mined by rebel groups and sold to fund military action against the country's government. The Kimberley Process: Tackling the Problem Worldwide concern over the problem of blood diamonds resulted in the Kimberley Process. In 2003, the European Union, 46 other countries, the United Nations, various NGOs, and human rights organizations came together in Kimberley, South Africa, to establish a set of rules to prevent the sale and purchase of blood diamonds. Since the establishment of the process, the trade of blood diamonds has fallen from 15% in the 1990s to less than 1% by 2010. Ethical Diamond Sourcing at Royal Coster Diamonds At Royal Coster Diamonds, we take great pride in being a reliable and ethical source for purchasing diamonds. Our company does not source any blood diamonds. Instead, we source conflict-free diamonds from Australia, Canada, Namibia, Russia, South Africa, and Tanzania. The profits from these diamond sales are used in a responsible way, such as investing in the country's infrastructure, education, and building hospitals near the diamond mining areas. We believe that a "good" diamond is one where the mining country's population benefits from the sales in some way.

The enchanting world of birthstones: A guide to the gems of each month

Birthstones have long been revered for their beauty and the unique qualities they are believed to bestow upon their wearers. From the deep red garnet of January to the vibrant turquoise of December, each stone carries with it a rich history and a set of meanings that resonate through time. In this detailed exploration, we delve into the significance and the lore surrounding these captivating gems. January: The Garnet The garnet, with its deep red hues, is the perfect emblem of the warmth and vitality needed to combat the cold of January. This gemstone is celebrated for its wide spectrum of colors and types, though the most renowned is the red garnet. The garnet symbolizes friendship, purity, love, protection, and the promise of safe travel and homecoming. It is also associated with medicinal properties, particularly benefiting the heart and circulatory system, and offering protection against poisoning. Notably, the garnet is linked with the two-year wedding anniversary and sometimes even the six-year milestone. It is also connected to the constellations Capricorn and Aquarius, as well as the rat in the Chinese zodiac. The name "garnet" has its roots in the Old English word "gernet," meaning "dark red". Want to own a birthstone that represents your birth month? Explore our bracelet and necklace options here. February: The Amethyst The amethyst, February’s birthstone, is a gem that exudes beauty, purity, and respect. Known for its stunning purple hue, it represents protection against intoxication, addiction, and helps promote skin health. The amethyst is believed to encourage positive thinking, protect from harmful thoughts, and alleviate physical ailments like abdominal pain and headaches. In astrology, it is linked to Aquarius and the dragon in Chinese astrology. The stone's name comes from Greek, meaning "not intoxicated," a nod to ancient practices of using the stone to ward off drunkenness. Thinking about getting a birthstone for your month? Discover our bracelet and necklace. March: The Aquamarine March's birthstone, the aquamarine, evokes images of the clear blue sea. This gem is thought to originate from the treasure chests of mermaids, bringing love, happiness, and healing powers. It stands for comfort, clarity, intelligence, creativity, and healing, particularly of throat and autoimmune diseases. The name "aquamarine" comes from Latin and means "water of the sea." Reflecting its oceanic color. Sailors once wore aquamarines to protect against the perils of the sea, believing in its power to bring harmony to relationships and its beneficial effects on health. Interested in your birth month's birthstone? Have a look at our bracelet and necklace. April: The Diamond April's birthstone, the diamond, is known for its strength, beauty, and love, making it the preferred choice for engagement rings. This gem represents power, magic, prosperity and protection from evil. The ancient Greeks and Romans thought diamonds were either tears of the gods or pieces of falling stars, giving them special qualities. In medieval times, people believed diamonds could make you fall in love and protect you in battles. At Royal Coster Diamonds we have our own diamond cut the Royal 201. The Royal 201 is a patented briljant. A regular brilliant has already a beautiful sparkle with 57 facets. But the Royal 201 exceeds this on every level. Want to celebrate your birth month with a birthstone? Check out our bracelet and necklace here. May: The Emerald The green emerald of May symbolizes rebirth and the flourishing of life that spring brings. It is associated with eternal youth, wisdom, love, and a peaceful spirit. The emerald’s vibrant green color is thought to have healing properties for the eyes and to foster love. It is particularly linked to the zodiac signs of Aries, Gemini, and Cancer. Want to own a birthstone that represents your birth month? Explore our bracelet and necklace options here. June: The Pearl June's birthstone, the pearl, with its soft, luminous beauty, stands for innocence, elegance, and tranquility. Pearls are unique among gemstones as they are created within oysters. They have been associated with numerous myths and legends, often seen as symbols of purity and wisdom. Looking to get a birthstone representing your month? Discover our bracelet and necklace here. July: The Ruby The ruby, with its fiery red color, is July's birthstone and symbolizes passion, protection, and prosperity. It is believed to bring good fortune to those who wear it on their left hand. The ruby's deep red color represents love and warmth, reflecting the intensity of summer. Thinking about getting a birthstone for your month? Discover our bracelet and necklace. August: The Peridot August’s birthstone, the peridot, is known for its light green color and is thought to protect against nightmares and bring the wearer power, influence, and a wonderful year. It is also believed to have healing properties and to attract love. Curious about buying your birth month's birthstone? See our bracelet and necklace here. September: The Sapphire The serene blue sapphire of September symbolizes wisdom, honesty, and good fortune. In addition to its heavenly color, sapphires are cherished for their connection to divine favor and protection. Despite being most known for its blue variety, sapphires exist in a rainbow of colors, each with its own unique significance. Want to celebrate your birth month with a birthstone? Check out our bracelet and necklace here. October: The Opal The opal, October’s birthstone, is famed for its play of color and mystical properties. It represents faithfulness and confidence. The opal is unique because it embrace the colors of other gems, offering protection and enhancing emotions and passions. Want to own a birthstone that represents your birth month? Explore our bracelet and necklace options here. November: The Topaz Topaz, the birthstone of November, shines with an array of colors but is most revered in its golden form. It symbolizes love, affection, and the power to heal and protect. Its wearer is said to gain strength and intelligence. Considering a birthstone for your birth month? View our elegant bracelet and necklace here. December: The Turquoise December’s birthstone, the turquoise, is prized for its striking blue hue and its calming influence. It symbolizes good fortune and success. Turquoise is believed to bring peace to the home and good health to the wearer. Interested in a birthstone that reflects your birth month? Discover our bracelet and necklace here.

The 4C's of Diamond Valuation

A diamond is the hardest natural material. It is formed deep inside the earth when carbon atoms are pressed together under high temperature and pressure, resulting in the formation of a crystal. These diamonds are then brought to the surface through volcanic eruptions or earthquakes. Not all diamonds are valuable. In fact, around 95% of natural diamonds are of poor quality and are unsuitable for jewelry. These diamonds are primarily used for industrial purposes or for polishing the diamonds that do have good quality. When a diamond is found, it is first polished by a professional diamond polisher. Based on their experience, the polisher has a general idea of the diamond's potential and makes an initial estimation of its carat, color, clarity, and cut. However, the final value of the diamond is not yet decided. The polished diamond is then sent to an independent certification authority for a closer examination. The certification authority measures and weighs the diamond, examines its color to determine its position on the diamond color scale, and investigates any inclusions using a microscope. Multiple experts review the diamond to minimize any potential errors. After the examination, the certification authority determines the final value of the diamond. It can now be sold and used in jewelry. At Royal Coster Diamonds we have different tours to give you more information about Diamond Valuation. The 1st C: Carat The weight of a diamond is expressed in carats. Carat is a unit of weight used for gemstones. The term "carat" comes from the French word "Carob," which refers to the seeds of the carob tree. These seeds have a consistent and universal weight, with an average of 0.2 grams per seed. To make it easier for customers and dealers, carats are divided into points. One carat is equivalent to 100 points, or 0.2 grams. For example, half a carat is 50 points and weighs 0.1 grams. This point system simplifies the measurement of weight for both sellers and buyers. The density of a diamond, also known as its specific weight, is 3.2 grams per square centimeter. The size of a diamond directly influences its price. Larger diamonds are rarer and therefore more valuable. Diamonds with a weight of half a carat (50 points) are the most found, while diamonds weighing over 0.5 carats are considered rarer. Diamonds with a weight of more than two carats are extremely rare, leading to a faster rise in price as the size of the diamond increases. The 2nd C: Color The color of a diamond is determined using verification stones, which come in various colors and gradations. Generally, diamonds with less color are more valuable. The color of a diamond is graded based on a scale that ranges from pure to impure, with pure diamonds being closer to the start of the alphabet. Diamonds are not limited to colorless or yellowish shades. They can be found in a wide range of colors, each with its own unique cause. Green diamonds have been exposed to radioactive rays and higher temperatures during their formation. Red, pink, orange, and brown diamonds have experienced damage to their crystal lattice during their journey from the core to the earth's crust, resulting in a different way of reflecting light compared to regular diamonds. Rarer colors such as blue, green, pink, and red are more valuable. Fancy colored diamonds are more expensive but if you want something similar with colored stones you can have a look at our Rainbow, Archive or Birthstone Collection. The 3rd C: Clarity Impurities in a diamond can take various forms, including black spots, cavities, fractures, and natural roughness. Black spots consist of carbon that is not fully crystallized, while cavities occur when a different type of inclusion gets ejected during the diamond's formation. Fractures are caused by the high pressure under which diamonds are created, resulting in small cracks. Natural roughness refers to small pieces of rough material that remain on the diamond after cutting, often visible as notches or slippery spots. The quality of a diamond's clarity is primarily determined by the size of these imperfections. Diamonds are graded based on the size of the imperfections, ranging from flawless (completely pure) to pique 2&3 (visible to the naked eye and affecting the diamond's sparkle). The placement of impurities during the cutting process can affect their visibility, and certain diamond cuts can more easily hide minor impurities. However, impurities in the cut have the least impact on the overall quality of a diamond. The 4th C: The cut The cut of a diamond refers to the way it is polished. Unlike the other three Cs, the cut is influenced by humans. Diamond cuts have evolved over time, with the earliest improvements involving simple polishing of natural facets in the mid-14th century. Different cuts have different characteristics and are preferred for various reasons. If you look at our gifting collection you can see jewelry with different diamond cuts. Transparent materials such as diamonds have a critical angle where light reflects internally on to the surface. Because of this reason, the cut of the diamond is extremely important. A diamond should be cut as close to the ideal cut as possible. If the cut is too deep or shallow, the light will get lost. Whereas when cut right, the light will be reflected and distributed. Each cut has its own standard, and the closer a cut is to the standard, the higher the value of the diamond. Properly cut diamonds reflect light in an ideal way, creating a brilliant sparkle. During the polishing process, about 60% of the raw material is lost, resulting in a more beautiful and valuable diamond. Royal Coster Diamonds has its own exclusive cut, the 'Royal 201'. This cut has 201 facets instead of 57, resulting in a greater sparkle in the diamond. Based on this cut, we have created the Royal 201 Signature C collection.

A Guide to Diamond Polishing: A Blend of Science and Craft

Diamond polishing is a precise and delicate process that requires both skill and in-depth knowledge of a diamond polisher. Polishing a diamond is a precise process that involves shaping and refining the rough stone to bring out its true beauty. The journey from a rough stone to a polished diamond involves several critical steps, each contributing to the gemstone's final brilliance and beauty. As the oldest, still operating, diamond polishing factory in the world, we invite you to visit our factory in Amsterdam. Diamond Polishing Preparation and Tools Before polishing can start, the diamond is split into two parts by a diamond cleaver. The larger piece is designated for polishing, while the smaller piece is used as a polishing tool. This tool, often a pyramid-like fragment, is essential because only a diamond can effectively polish another diamond. The primary tools in diamond polishing include a cast iron polishing wheel, diamond powder, and olive oil. The polishing wheel, known for its durability, is essential for achieving the desired finish. Diamond powder, consisting of fine diamond grains, is used to achieve various levels of coarseness. Olive oil serves as a lubricant, ensuring the wheel operates smoothly without unpleasant odors when heated. Polishing Wheel Preparation The polishing wheel must be meticulously prepared before use. This involves clamping the disc between two pieces of lignum vitae wood to ensure it is level. A pumice stone is then used to smooth the surface, followed by a thorough cleaning and degreasing with ammonia and methylated spirits. Applying Oil and Diamond Powder Olive oil is applied to the wheel at regular intervals, typically every 5 centimeters. Diamond powder is then evenly distributed over the surface. This mixture is worked into a thick, dry paste by rubbing in small circles, creating the perfect medium for polishing. The Polishing Process Once the wheel is prepared, it must be "settled" by working the diamond powder and oil with a diamond held in tongs. The wheel is divided into an inner "test circle" for testing the diamond’s facets and an outer edge for actual polishing. Operating at speeds of 3000 to 3800 rotations per minute, the wheel is perfectly calibrated for the polishing process. Experience the diamond polishing process up close with a free guided tour of our factory. The history of diamond polishing Amsterdam has long been known as the Diamond Capital of the World due to its rich history and expertise in diamond cutting and polishing. The city has been at the forefront of diamond craftsmanship since the 16th century. Innovations in cutting machines and technologies have solidified Amsterdam's reputation as a leading center for transforming rough diamonds into exquisite gemstones. Visitors can explore Amsterdam’s diamond history and craftsmanship. The city’s diamond district showcases this heritage, with Royal Coster Diamonds being one of the most renowned diamond cutting facilities and the oldest diamond polishing factory still operating. It’s possible to visit the Royal Diamond House of Amsterdam and participate in tours and workshops. The Importance of Cut Quality The cut of a diamond significantly influences its overall appearance and value. This process involves more than just shaping the stone; it’s about achieving the optimal interaction with light to create maximum brilliance. Read an in-depth report about grading a diamond. Facets and Light Performance A diamond's facets are like tiny mirrors that reflect light within the stone. A typical round brilliant cut diamond has 57 to 58 facets, which must be precisely aligned to enhance the diamond's sparkle. The quality of these facets, their angles, dimensions, and arrangement, play a crucial role in determining the diamond’s brilliance. Key Aspects of Diamond Cut Quality Polish: The overall quality of the diamond’s facet surfaces, evaluated for any imperfections resulting from the polishing process or wear. Polish is graded on a scale from Excellent to Poor. Symmetry: The precision of the diamond's shape and the alignment of its facets. Symmetrical diamonds display consistent brightness. Poor symmetry can result in reduced light performance and diminished brilliance. Cut Grade: Determined by factors such as brightness, scintillation, weight relative to diameter, girdle thickness, and the quality of facet polish. The cut grade ultimately defines the diamond’s ability to reflect light effectively. See our polishers at work at our Diamond Factory. Book a tour and learn about the royal heritage of Royal Coster Diamonds and the craft of diamond polishing while you also learn everything you need to know about diamonds.

The 2nd C: The Color

The color of a diamond –or rather the lack of it – tells us something about the value and quality of the diamond. A diamond that consists of carbon only is pure white. This is the highest quality and the rarest form of a diamond. If the carbon is polluted with for example nitrogen, the diamond will be a yellowish or light brown color. The more a diamond is affected, the lesser bright its color is. Explanation of the second C (Color) by our Chief Purchasing Officer Our Chief Purchasing Officer helps you to understand the basics of the 4 C’s of diamond valuation. A more detailed explanation, you find below this video. The color of a diamond The color of a diamond is determined by using verification stones. These are diamonds in all different colors and gradations. Usually goes: the less color, the more valuable the diamond is. However, it is not like yellow(ish) colors are worthless. An example is a yellow stone that was recently sold at an auction for 8 million euros. Quite something for a polluted stone don’t you think? Below is a scale with the current and old names, that explains how a diamond is graded based on color and the absence of it. The closer to the start of the alphabet, the purer the stone. Colored stones Colorless and yellowish stones are not the only possible colors for a diamond. Diamonds are found in every color imaginable. Something happened to every diamond that is not white or yellow. A blue diamond, for example, is polluted with boron. A green stone has been in contact with radioactive rays during the formation of the diamond and was also exposed to a much higher temperature than it normally would be. Within a red, pink, orange or brown diamond, the crystal lattice has been damaged during the transport from the core to the earth’s crust. The crystal lattice is the way the atoms are connected to each other. When these atoms are shifted, it will damage the lattice. This cause the light to reflect in a different way than it does for regular diamonds. Blue, green, pink and mainly red diamonds are the rarest colors and are therefore the most valuable diamonds. Learn more about colored diamonds and gemstones Both colorless and colored diamonds are stunning because of their amazing sparkle. The fairest colored stones and diamonds can be seen during a Royal Experience. Our experienced guides love to tell you everything about the 4 C’s as well. The other C's: > The first C, Carat> The third C, Clarity> The fourth C, Cut

The 1st C: The Carat

For many people, buying a diamond is not an everyday business. It seems quite difficult already. But if you dive deeper in the world of diamonds, it appears even harder to make a choice. How can two seemingly similar diamonds differ so much price-wise? The difference in price can depend on the seller. That's why it is always more beneficial to buy diamonds straight from the source. However, the diamond prices at a diamond store vary as well. This is because a diamond’s value depends on the 4 C’s of diamond valuation. The 4 C’s are carat, cut, color and clarity. The first C to examine in this series is Carat. Explanation of the first C (Carat) by our Chief Purchasing Officer Our Chief Purchasing Officer helps you to understand the basics of the 4 C's of diamond valuation. A detailed explanation, you find below this video. The weight of a diamond Carat is the weight of a diamond. We use carat actually to express the weight of all gemstones. Carat comes from the French word Carob. Carobs are the seeds of the fruit of the carob tree. These seeds are distributed very evenly and universal weight. On seed weighs on average 0.2 grams. Carat indicates the weight of a diamond. But to make it easier for customers and dealers, the carats are divided into points. One carat is 0.2 grams and 100 points. Half a carat is 50 points and weighs 0.1 grams. A quarter carat is 0.05 grams and thus consists of 25 points, and so on. This point system makes it easier and clearer for both the seller and the buyer. The density of a diamond – the specific weight – is 3.2 gram per square centimeter. The bigger the diamond, the higher the price It is no surprise that the size (among other things) determines the price of a diamond. The larger the diamond, the more the price (exponentially) rises. This has to do with rarity. Diamonds to half a carat (50 points) are the ones that are most commonly found. Therefore, we consider them relatively ordinary. Diamonds over 0.5 carats are rarer. And diamonds of more than two carats are extremely rare. This causes the price to rise faster as the diamonds become bigger. The cutting method determines the size of the diamond The way a diamond is cut, influences the weight of a diamond. A thick girdle (top) or belt (circumference of the diamond), make the diamond a few points heavier. A "steeper" cut diamond, is heavier than a “flatter” cut one. One should always start with assuming that the diamond is cut according to the standardized rules. According to these rules, the diamond has a certain weight. We call this standard is the “ideal diamond cut”. It is not cut too steep and not cut too flat. Recognizing a fake diamond based on carat The carat can be a guideline to find imitation diamonds. Because a diamond with a given diameter has a certain weight. If that weight differs much from the norm, it is probably not a real diamond. Exponential price differences between above and below round carats The weight also affects the price in a certain way. For example, 0.99 carat is substantively worth less than a stone of 1.01 carats. This can be as much as a 15% difference in price. That's why a cutter always tries to end just above a round number. He prefers to cut a diamond 1.51 rather than 1.49 and 1.01 over 0.99. The difference between just above and below a round number causes a larger price difference than between, say, a 1.03 and a 1.01-carat diamond. How many carats is my diamond? Each diamond shape has a different formula to calculate the carat of a diamond. The formula to calculate the weight of a brilliant cut diamond is: Height x diameter ² x 0.0061 This is according to the standard. A large difference is an indication of bad polishing or an imitation. Every kind of cut has its own formula to calculate the weight. So there’s a different one for emerald cut, heart shaped diamonds and a princess cut for example. Weighing a diamond with a scale Today, we weigh diamonds with an electronic scale. Before, we used a mechanical one. With an electronic scale, weighing is a lot more accurate. It is even possible to calculate up to the 3rd digit after the decimal place. The scale that is used to weigh diamonds should be checked at least once a year by an official qualified company. Preferably, multiple times a year. Diamond weighing for free It remains always difficult to determine the weight or the carat of a diamond yourself. Therefore we encourage you to visit our store in Amsterdam. Our diamond polishers are happy to weigh your diamond for you. You finally know exactly how many carats your diamond is. Combine your visit with a diamond factory tour or book a Diamond Masterclass to learn everything about diamond evaluation. In the Masterclass, you will learn among other things, how to determine a diamond’s carat yourself and about the 4 C's of diamond valuation. Read about the other C's: The other C's: > The second C, Color> The third C, Clarity> The fourth C, Cut

Brief History of Diamonds

In the hectic days of constant rushing around, the little sparkle of a diamond helps you pause for a second and forget about the worries of the world. Take that relaxing sigh for a split second as you behold its magic. A diamond’s sparkle can soften a heart and even if just for a short while, it makes you feel like you belong to a fairy tale world. But what makes diamonds so beloved? Take a brief trip through the history of diamonds. An ancient love for diamonds Did you ever wonder about the origins of this magnificent marvel? To learn more about its history, we have to go back as far as the 4th century BC. According to most theories, man first came across diamonds in the land of India. At first, diamonds were therefore only traded in India. But after Alexander the Great brought the first diamonds to Europe in 327 BC, the public and especially elite fell in love with the gem in no time. From rough to polished However, before the diamond gets its dazzling quality, it goes through a refinement process. The diamond’s journey starts in the deepest layers of rocks. Shaking and rumbling grounds, either by nature or manpower, forcefully eject the stones from their cradle. After being removed from its “bed”, the diamond goes through a lot of processes, like cutting and polishing. Only after these processes, the diamond comes in display at the jeweler’s store. Thus, after all the final touches, the once rough and jagged stone becomes a magical gem displaying brilliance and grace. New diamond cuts As diamonds gained mainstream popularity, new shapes and designs emerged. Around 1375, one of the very first designs appeared: the Point Cut. This design matched the natural contour of the diamond. The Point Cut’s predecessors were only naturally well-shaped diamonds. Diamonds that came in in rough and jagged form, were not attention worthy. After all, there were no cutting masters around to polish it into a particular shape. New marketplaces Sources of the diamond marketplace changed throughout the years. As mentioned before, it started in India. Then the trade and selling shifted to Europe. By the 18th century, people discovered diamonds in Brazil as well. So, even though the diamond was an exclusive piece in the past, it is now equally available throughout the world. The modern diamond trade started in Africa, where they discovered diamonds in 1866. Towards the beginning of the 20th-century, people discovered diamonds in the U.S. as well as Canada and other newly discovered places. Due to its value and high demand, mining for diamonds also shifted from surface to underground mining. Eternal beauty Needless to say, it was becoming more and more popular, especially among the elite. Women and as well as men enjoy this sparkling beauty, which seems to put a smile on everyone’s face. New knowledge about its different properties and ways of handling has also sprouted during this time, which led to creating pieces of perfection. To this day, the diamond remains the most valuable gem in the world and its splendor appears to shine through centuries. Want to learn more about diamonds? Book a tour and learn about the royal heritage of Royal Coster Diamonds and the craft of diamond polishing while you also learn everything you need to know about diamonds.

The 3rd C: Diamond Clarity

The 3rd of the four c’s we discuss in this series is the clarity of a diamond. A natural diamond is rarely without imperfections. It is a hallmark of Mother Nature to show that nothing is perfect. To evaluate a diamond’s clarity, we use a 10x magnifying glass. This is the tool everyone uses to have unity in the outcome. Under a microscope, you will always see impurities. Explanation of the third C (Clarity) by our Chief Purchasing Officer Our Chief Purchasing Officer helps you to understand the basics of the 4 C’s of diamond valuation. A more detailed explanation, you find below this video. Types of impurities in diamonds Imperfections in a diamond can have various causes. Generally, the impurities are black spots, cavities, fractures, or natural roughnesses: 1. Black spots consist of carbon that is not fully crystallized.In a diamond, these look like dots, spots, feathers or dashes. 2. Cavities inside the diamond.Just like a cavity in a tooth, a diamond can have a cavity. It can form anywhere on or in the diamond and differ in size. A diamond is a natural product and something can happen during the formation of it. A cavity occurs when a different type of inclusion (like a crystal or black spot) gets dislodged when the diamond surfaces. When the diamond gets to the surface with great force, the original inclusion can fall out and leave a "gap" or cavity. 3. Fractures in a diamond arise as well during the formation.A diamond is created under very high pressure; this pressure can deform the diamond. The deformation can cause small fractures in the diamond which appear as minor impurities. 4. Natural roughnesses are ‘raw’ pieces on a diamond.A grinder or diamond cutter can cut the diamond very efficient or too thrifty. He does this because he doesn’t want to lose too much of the diamond during the grinding or cutting process. When a diamond worker cuts the diamond too parsimonious, small pieces of roughness can remain on the diamond. This is visible on the diamond as a small notch or a slippery spot. Often this is at the girdle (the diamond’s widest part) and at the lower part of the adjacent facets. Gradations of clarity in diamonds Besides the different types of impurities, the quality of the clarity depends primarily on the size of the imperfections. This size determines the diamond’s clarity label. The sizes of the imperfections are listed as follows, from left to right and from pure to impure: Flawless diamond clarityCompletely pure diamond, free of impurities. These kinds of diamonds are very rare. VVS 1&2 diamond clarityVVS means very, very small imperfections. Even with a 10x magnifying loupe and a highly trained eye, you can barely see them. VS 1&2 diamond clarityVery small imperfections. If you look closely through a 10x or more magnifying loupe, you’ll be able to see them. SI 1&2 diamond claritySmall impurities that can be seen with a 10x magnifying glass. These imperfections, however, don’t affect the diamond’s sparkle that much. Pique 1 diamond claritySmall impurities which are visible under a magnifying glass. If you look closely, you can perhaps even see them without a magnifier. These impurities nevertheless do little of the diamond’s sparkle because of the location inside the stone. Pique 2&3 diamond claritySmall impurities which are visible to the naked eye. They are visible to the naked eye and can dull the diamond's sparkle somewhat. Impurities in the cut Impurities in the diamonds are the least affecting factor in the 4 C's. Up until the SI, imperfections are not visible to the naked eye. However, a pique diamond can be placed into a piece of jewelry in such a way, that the imperfections in this diamond aren’t visible either. A good diamond cutter will always consider the placement of the impurity during the grinding process. If a black spot appears in the collet (the bottom tip), it can reflect 8 to 24 times more. In that case, a tiny speck can look like a huge horrifying impurity. Exactly, for this reason, it is so important to have a diamond that was cut by a professional. The cut of the diamond affects the visibility of imperfections as well. Brilliant cut diamonds, such as the Brilliant, Princess, Oval, Pear, Marquise and Heart shape can more easily hide minor impurities. This is in contrast to other shapes like the Emerald, Asscher, and Baguette cut. These cuts have a larger table and impurities show grim. Tips for buying a diamond If you really want a diamond without impurities, you should take a VVS diamond or higher. Note however that only a small 10% of all diamonds that are found have this clarity. The most popular purity is VS. These stones appear pure to the naked eye and the impurity can only be found with a loupe. About 50% of the stones that are found are within this category. This also makes them instantly much more affordable than VVS or higher. After VS, there’s the SI. This category has impurities that are too small to be seen easily without a magnifier. People often choose SI diamonds, so they can afford a higher carat, purer color or better cutting shape. By downgrading the clarity, you can often upgrade on one of the other C’s. The bigger the stone, the more important the diamond’s clarity is. This is because it is, in fact, easier to spot impurities on a big stone. For stones larger than two carats, we encourage you to take a diamond with a purity of at least SI. At large pique diamonds, spots can often be visible. Want to know more about the 4 C’s? Do you want to know more about the 4 C’s of diamond evaluation? Then you may want to read the articles about the carat, cut and color or book one of the tours through our diamond factor. Our experienced guides would love to tell you everything about the 4 C’s as well. The other C's: > The first C, Carat> The second C, Color> The fourth C, Cut

The 4th C: Diamond Cut

The fourth of the four C’s in this sequence is the Cut, or shape of a diamond. The shape is important to determine the quality of the polished diamond. The shape a diamond will become depends on the diamond quality and the amount of material loss in the process from rough to polished. Explanation of the fourth C (Cut) by our Chief Purchasing Officer Our Chief Purchasing Officer helps you to understand the basics of the 4 C’s of diamond valuation. A more detailed explanation, you find below this video. Diamond cuts A good diamond worker can cut a diamond in almost every shape imaginable. However, it is important that the cutter keeps the way the light reflects in mind. There are several preferred cuts: the brilliant, emerald, princess, marquise, pear, heart, oval, cushion, Asscher and baguette. Brilliant diamond cut The most popular and common diamond shape is the brilliant cut. Almost 95% of all diamonds are this particular shape. This is because the brilliant diamond has the most value and reflects the light in the best way possible. Another reason a brilliant is so popular is that it is suitable for use in most kinds of diamond jewelry. Royal 201 diamond cut The Royal 201 is a patented brilliant by Royal Coster Diamonds. A regular brilliant has already a beautiful sparkle with 57 facets. But the Royal 201 exceeds this on every level. This brilliant has no less than 201 facets. The 201 facets reflect the light perfectly. It makes this cut the most sparkling diamond shape in the world. You can see the difference between a regular brilliant and our Royal 201 during one of the tours at our diamond polishing factory. Emerald diamond cut The emerald cut is named after the well-known green stone that is cut often in this way. The emerald cut has a reputation of a luxurious diamond shape. This is because any small imperfections are highly visible in this kind of cut. Visible inclusions make the diamond less valuable. That's why we use pure and luxurious diamonds for emerald cuts. But they come with a matching price tag. The emerald cut engagement ring is very popular by celebrities such as Kim Kardashian and Angelina Jolie. Princess diamond cut The second most popular diamond shape is the princess cut. This square cut with straight lines has a beautiful sparkle. The angular shape makes this type of diamond great for usage in different kinds of jewelry. Princess cuts are for diamond engagement rings, earrings, and bracelets. Marquise diamond cut Named after the Marquise of Pompadour (the mistress of Louis 14th) is the marquise cut. The pointed ends of this cut optimize the light reflection within the diamond. But they also make the diamond to appear bigger. The marquise is almost exclusively used in rings, sometimes combined with small stones surrounding it. Pear diamond cut We know the pear cut or pear-shaped diamond also as a teardrop diamond. This cut looks like a combination of the round brilliant shape and a marquise. The pear-shaped diamond is loved because of its elegant look. A pear-shaped diamond on a ring makes the finger appear longer. In earrings and necklaces, pear cut diamonds are also very popular because they accentuate the length of the neck. Heart diamond cut The heart-shaped diamond is a variant of the pear cut. It is perhaps the hardest diamond shape to create because it takes advanced skills to create symmetry. It’s no secret that a heart stands for love and that diamonds are the international symbol for love as well. Therefore, heart-shaped diamonds are very popular gifts. You can find heart shapes in any kind of diamond jewelry. Oval diamond cut Oval diamonds have a reputation of prestige and luxury. This is because many famous diamonds are cut in an oval shape – the Koh-I-Noor for example. But also women with short or wide fingers often prefer to wear oval diamond rings. Because the oval shape makes the fingers look more slender; in contrast to for example the brilliant cut. This gives an overall more luxurious look. Moreover, in terms of sparkle, the oval diamonds come closer to the round cut than any other shape. Little of the brilliance is lost. Cushion diamond cut The cushion cut is sort of a combination of the princess and oval cut. This diamond shape is often described as a rectangle or square with rounded corners. The cushion-shaped cut is over 100 years old. Especially in the 19th century, it was very fashionable. In 1930, the shape became popular again. Nowadays we consider the cushion cut diamond a classic and romantic shape. It distinguishes from modern polishing techniques. Radiant diamond cut Like the princess, the radiant cut is a square shape. But like the cushion diamond, the radiant has round corners. The way the radiant is cut is similar to the emerald cut, combined with the way facets are created on a brilliant. The radiant has no less than 70 facets. You could say the radiant is actually a combination of many different cuts. In recent years the radiant became increasingly popular in diamond engagement rings. Often these are solitary rings. Asscher diamond cut The Asscher cut originates from Dutch soil. In 1902 the Asscher brothers cut a square diamond the same way an emerald is cut. This way, they created a completely new diamond cut. Due to the large square table (top of the diamond), the color and clarity of the diamond are beautifully shown. Baguette diamond cut Like the cushion diamond, the baguette is also a ‘fancy cut’. This cut was especially popular in the Art Deco period. Baguettes are rarely the main stone in any diamond jewelry. They are often placed to the center stone. The standard Each cut has its own standard. The closer the cut is to the standard, the better it is qualified and the higher the value of the diamond. The diamond is qualified as: Good Medium Poor The standard for the brilliant is as follows: size of the table: 56% of the girdle the height of the crown: 11-17% of the whole and at an angle of 34.5° Size of the girdle: very thin to medium corner pavilions: 8° If a brilliant cut meets the requirements above, its gets qualified as ‘good’. When a diamond is grinded badly, this can lead to a loss in value of 6 to 15%. For bad cuttings even more! A diamond with poor grinding gets therefore qualified as ‘poor’. The sparkle It is important that the diamond polisher cuts the angles of a brilliant at a proper degree. The angles relate to the reflection of light within the diamond. When the corners are too steep, light gets out from the sides. But when the corners are too flat, the light continues to reflect until it decays in dead corners. The light is lost and leaks through the bottom of the crown. If the diamond has a proper cut, the light reflects in the ideal way. It travels through the table, the pavilions and the bezels of the top straight up. This creates an unsurpassed, perfect brilliant sparkle. The weight lost A rough diamond looks like a chunk of white or colorless stone. It does not sparkle, or at least not a lot. During the polishing process, we lose about 60% of the raw material. This is due to the sawing of the stone, the cutting, the grinding, and the polishing. This may seem like a waste. But because of the grinding loss, the diamond becomes even more beautiful and valuable. This principle led to the saying: "everybody wants to be a diamond but few are willing to get cut". Smooth The finished cut affects the price. The cutter must ensure that the facets are beautifully ‘sweet’. This means that the facets have no cutting stripes and have a nice smooth finish. All diamond cuts are possible Besides the best-known diamond cut, there are a lot of other shapes possible to cut a diamond into. Our diamond cutters have truly mastered the art of diamond polishing. You can see them creating diamond cuts in a Royal Experience tour and learn more about the 4 C’s of diamond valuation. Our experienced guides love to tell you everything about the 4 C’s as well. Do you want to cut a diamond yourself? Assign for our Diamond Masterclass. You’ll learn all there is to know about diamond cutting. The other C's: > The first C, Carat > The second C, Color > The third C, Clarity

What is a Diamond Certificate?

Carat, color, clarity, and cut. These are the so-called 4 C's. You take them into account you're about to make one of the most important purchases of your life. But before you start dreaming about that sparkling beauty, let's talk about another Big C. The Certificate. Do all diamonds come with a certificate? No. Only high-quality diamonds come with a certificate. The certificate is basically a report. A report that proves that all of the C's are in place. It is a written document that guarantees the diamond quality. There are quite some evaluating agencies. The certificates vary based on the agency that issued the report. How does a diamond get certified? With various high-powered microscopes in special laboratories. Professional gemologists use them to measure and study the diamond's symmetry, color, size and shape. They also pay great attention to certain flaws and the quality of the cut. Once the gemologists determined all the different properties, they attach a report to the diamond. The report holds an accurate description of the examination. Sometimes, the gemologists use high-level heat or lasers to improve certain properties of the diamond. Trustworthy agencies put these enhancements on the report as well to inform the buyer about the “upgrade”. Which diamond certificates can I trust? But how do you know which diamond certificate is legit? If you are not familiar with diamond institutes (because: why would you?), you can be fooled with a fake certificate. That's why you need a certificate from a trustworthy organization. Here’s a list of some of the most famous grading agencies across the United States and Europe: International Gemological Institute (IGI) Gemological Institute of America (GIA) American Gemological Society (AGS) European Gemological Laboratory (EGL) Diamond High Council (HRD, which is an abbreviation of the Dutch “Hoge Raad voor Diamant”) International Confederation of Jewelry, Silverware, Diamonds, Pearls, and Stones (CIBJO) If you have a diamond certificate from one of these organizations, you know you did good. Certificate vs. warranty Another advice for diamond shoppers is to get a warranty. Besides a written proof of the diamond’s value, a warranty serves as a safety net in case something happens to the piece of jewelry. Diamond is the strongest material known to man, but it is not indestructible. It can crack or get scratched. If this happens, you can use the warranty to salvage the situation. At Royal Coster, all our diamonds come with a lifelong warranty. It's all about trust Overall, we highly advise you to take a certificate with your diamond-related purchases. Not only to have a written document that proves the value of your investment, but also for your own conscience. It is surprising how quickly certain ill-intended jewelers choose to take advantage of the situation and lure inexperienced shoppers into buying faux diamonds. Avoid such scenarios, and do adequate research about the seller before buying the diamond. After all, it is a serious investment. So, taking a bit of extra time and effort definitely pays off in the long run.

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