Process Analysis: Natural Diamond Formation

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  • Topic: Diamond, Carbon, Synthetic diamond
  • Pages : 5 (1580 words )
  • Download(s) : 52
  • Published : May 27, 2011
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"Better a diamond with a flaw than a pebble without" (Confucius 1). It is a common belief in today’s day and age that it is better to be something of value that is flawed than to be something of no value that has no flaws. Diamonds are formed from pure carbon, which is one of the most abundant elements on planet Earth, and makes up about 18% of the human body. In fact, all life on earth is carbon based. Even from ancient times diamonds have been sought for their extraordinary hardness (they are the hardest substance known to man) and exceptional beauty. In the modern world, when given the choice most people would purchase a two carat natural diamond over a one that was man made of the same price, even though they could get nearly three times the size of stone. After all, if you were the one spending three months’ of your salary on a rock would you want the fake one? Not to mention you darlings reaction when she finds out that her beautiful new diamond ring is not real. In nature there are many components that are involved in the creation of a diamond.

There are very few naturally occurring elements involved in the creation process of a diamond. First and foremost is carbon, which is the main element present in the structure of any diamond. While most people know carbon is the element that makes up the lead of a common pencil, it is also the main element found within a diamond. Make no mistake, the carbon that is found in a diamond is very different from that found in graphite. In the case of a diamond, the carbon atoms are tetrahedrally bonded, causing the carbon atoms to crystallize into what is known as a diamond lattice, which is a variation of the face centered cubic structure. A diamond structure that has very few inclusions or impurities will be what is known as “colorless” and will appear clear. These diamonds with little to no impurities are often used as electrical insulators due to the non-conductivity of the carbon. As stated in the McGraw-Hill Encyclopedia of Science & Technology, “Although diamond consists of carbon, at least 58 other elements have been found (for example, aluminum, 10 parts per million: hydrogen, 1000 ppm: silicon, 80ppm) as impurities in natural diamond” (446). On occasion, boron or nitrogen atoms will replace a small amount of the carbon atoms in the lattice structure during creation. These diamonds are referred to as boron-doped diamond (BDD) and nitrogen-doped diamond (NDD). These diamonds that have had some of the carbon atoms replaced by a small amount of boron/nitrogen during the creation process have noticeable differences. The boron impurities cause the diamonds to have a blue to blue gray coloring. On the other hand if the diamond has a nitrogen impurity, it will have a color that ranges from yellow to brown. The impurities in both the boron and nitrogen doped diamonds make them different in other ways as well, BDD for example is a natural semiconductor, while the NDD on the other hand is used in water treatment due to its electrochemical reactivity. It does however take a little more than chemistry to create a diamond.

Diamonds are formed by the prolonged exposure of carbon bearing materials to high pressure and temperature. The formation of natural diamonds starts in upper part of the Earth's mantle, where the temperatures range from 900o – 1,200 o C. It is helpful if one puts that into a somewhat fathomable perspective, try thinning of it as being nearly ¼ as hot as the surface of the sun. As the carbon atoms get hotter and hotter they begin to bounce around and slam into each other. During this period of rapid movement and heat, each of carbon atoms bond with four other atoms forming the diamond lattice. The more time the carbon atoms are exposed to this extreme heat, the more chances each atom has to bond with others allowing the crystal structure of the diamond to grow larger. The pressure needed to form the diamond...
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