“Diamonds!” the first thing you usually hear as the familiar Jewelry Exchange commercial begins. Regardless of whatever specific styles of diamond jewelry that happens to be advertised in the commercial at that time, you already know what the Jewelry Exchange is all about. Diamonds. No other gemstone on this planet is more sought-after. Other gemstones are definitely just as prized and adored. Sapphires, rubies, emeralds, and pearls all rate very highly as precious, valuable objects and are obviously widely cherished; yet no other gemstone but a diamond has the favorable disposition to be so central to the ubiquitous act of two people getting engaged to wed. The diamond is the universally acknowledged symbol of the union of marriage. And why not? A diamond is the hardest substance on Earth, and what could possibly serve as a more fitting symbol of holy matrimony and an unbreakable bond between two people? Aside from its cultural significance and popularity within matrimonial customs, a diamond by its very nature is an endlessly fascinating and unique phenomenon representative of truly amazing physical properties. Diamonds are actually a form of carbon of which the atomic bonds have been modified into a completely different structural form. A diamond’s inherent material properties are caused when carbon is composed in an arrangement consisting of interlocking triangular pyramid structures, or tetrahedrons. To really understand the difference that varying arrangements of carbon atoms can have on the resulting material structure of a substance, recall that graphite is another structural form of carbon. The only difference between it and a diamond is that the carbon atoms are arranged in stacked, flat hexagonal lattice sheets, instead of an array of 4-sided tetrahedral shapes that are three-dimensional in nature and arranged so that they lock together to form a cube shaped unit. This is known as a diamond lattice, or more accurately, a diamond cubic. The strong interlocking arrangement of the carbon atoms that make up the diamond cubic is largely responsible for the substance’s longstanding reputation (since antiquity) for hardness. The name itself comes from the ancient Greek word adámas, which meant “unbreakable”. In the present day, hardness of a material is measured by a method known as the ‘Mohs scale of mineral hardness’. This process rates materials on a 1-10 scale based their resistance to being scratched by the sample benchmark minerals listed; minerals that found their historical rank on the scale by being resistant to scratching by the listed mineral lower on the scale. Talc is at the very bottom because it is soft and easily scratched by nearly anything. Gypsum can easily scratch talc, but cannot scratch calcite, which in turn can scratch gypsum; therefore gypsum and calcite are ranked 2 and 3, respectively. This hierarchy of mineral scratching, and subsequent resistance to scratching reaches the top of the scale at number 10, the hardness ranking of a diamond. It has the ability to scratch all known minerals, but cannot in turn be scratched by any of them. As the undisputed “king of hardness”, a diamond also takes a starring role in a popular device to test a material’s hardness in industrial applications, the Vickers hardness tester, which uses a diamond cut to a square-based pyramid and uses this to measure the relative rate at which an object can withstand being indented by this implement by using a fixed amount of pressure to bring into contact the diamond indenter with the surface of the material to be tested. This inherent hardness makes a diamond ideal for two situations; instances in which things need to be cut, scratched, or gouged, and alternately, in instances in which you want something protected from being cut scratched or gouged. In the former situation, diamonds have many useful heavy industrial applications, mainly putting their hardness to good use in cutting tools, drills, and other instruments that are required to effectively pierce, cut, grind, or polish. Then of course when it comes to the latter situation, when you want something that is relatively resistant to damage, a diamond makes the ideal gemstone to showcase in fine wearable jewelry since it is so durable and holds a polish so well. However, a diamond’s most prized characteristic is probably the magic that is created when a rough diamond is shaped and cut into a gemstone. While the hardness of a diamond is undisputed, a diamond is still capable of being cleaved by a skilled craftsman wielding specially-crafted cutting tools (diamond tipped, of course). Once shaped, the fire of color that results after the light enters the diamond’s table then reemerges after reflecting off the facets within, catches the eyes joyously and fascinates the imagination. People have been drawn to the diamond for these very reasons and more since time immemorial. While the name of the gem originated from ancient Greek, it was in Sanskrit, one of the languages that the people of ancient India used, that we find written the first historical mentions of diamonds in still-surviving texts. The ancient Indians were among the first to revere diamonds as precious gemstones, describing them in the ancient texts and mentioning the local trade markets for the gemstone, of which India was at the center. Due to this trade, other cultures came to know about the splendors of a diamond, while also discovering its noteworthy usefulness in cutting, engraving, and more. For millennia, India was the essentially the only place in the world where you could find diamonds in relative abundance, that is until 1725 when they were found in Brazil, and then again in 1867 when they were found in immense quantities in South Africa, which would become a significant turning point in the history of diamonds.