Archive for the ‘Diamond History’ Category

Diamond Education/History Part Six

Tuesday, January 8th, 2008

    Diamonds are first recognized and mined in India.Diamonds have been known in India for at least 3000 years but most likely 6000 years. The most familiar usage of diamonds today is as gemstones used for adornment a usage, which dates back into antiquity. In the twentieth century, experts in the of field of gemology have developed methods of grading diamonds and other gemstones based on the characteristics most important to their value as a gem. Four characteristics, know informally as the four C’s are now commonly used as the basic descriptors of diamonds, which are carat, cut, color and clarity.

               

      The diamond industry can be separately into two basic distinct categories, one dealing with gem-grade diamonds and another for industrial-grade diamonds, while a large trade in both types of diamonds exist, the two markets act in dramatically different ways.          

      Precious metals such as gold or platinum, gem diamonds do not trade as a commodity. Ninety-two percent of diamond pieces cut in 2003 were in Surat Gujarat, India. 

          The production and disruption of diamonds is largely consolidated in the hands of a few key players, and concentrated traditional diamond trading centers. The most important being Antwerp, where 80% of all rough diamonds, 50% of all cut diamonds and more than 50% of all rough, cut and industrial diamonds combined are handled.

            The De Beers diamond advertising campaign Is acknowledged as one of the most successful and innovative campaigns in history. N.W. Ayer & son, the advertising firm retained by De Beers in the mid-20th century, succeeded in reviving in the American diamond market and opened up new markets, even in countries where no diamond tradition had existed before. This coordinated campaign has lasted decades and continues today; it is perhaps best captures by the slogan “a diamond is forever”

Diamond education/History Part five

Monday, January 7th, 2008

Diamond and meteorite impact craters

     Microdiamonds are very small diamonds, they have been found in meteorite impact craters. Such impact events create shock zones of high pressure and temperature suitable for diamond formation. Microdiamonds can be used as one indicator of ancient impact craters. 

Extraterrestrial diamonds          

     Not exactly all diamonds found on earth originated here. About 3 billion years ago a type of carbonado diamonds that is found in South America and Africa was deposited their via an asteroid impact.(not formed from the impact) 

Surfacing 

Schematic diagram of a volcanic pipe     

Diamond-bearing rock is brought close to the surface through deep-origin volcanic eruptions. The magma for such a volcano must originate at a depth where diamonds can be formed. The pipes are open during surface eruption. Not all pipes contain diamonds, and even fewer contain enough diamonds to make mining economically viable.                

     Certain indicator minerals typically occur within diamondiferous kimberlites and are used as mineralogic tracers by prospectors, who follow the indicator trail back to the volcanic pipe, which may contain diamonds.               

      Once diamonds have been transported to the surface by magma in a volcanic pipe, they may erode out and be distributed over a larger area. A volcanic pipe containing diamonds is known as a primary source of diamonds. Secondary sources of diamonds include all areas where a significant number of diamonds, eroded out of their kimberlite or lamproite matrix, accumulate because of water or wind action. These include alluvial deposits and deposits along existing and ancient shorelines, where loose diamonds tend to accumulate because of their approximate size and density. Diamonds have rarely been found in deposits left behind by glaciers. 

The Case of the Mysterious Champagne Diamond

Tuesday, September 18th, 2007

I came across this video clip all about the history of diamonds, it is pretty funny. Enjoy it.

http://www.jcoc.tv/view_video.php?id=153

Moshe