Diamonds are the most precious stones in the market today. They are precious mostly because it takes a long time for it to form, as well as that it is one of the most durable minerals. Most people though think little of how diamonds are formed. Now large diamonds are being examined to know how the inner Earth works.
Large diamonds are exceptionally rare. While diamonds in itself are rare enough, large ones in particular are very rare. Researchers though are looking at some of the largest diamonds today to know how they have been formed.
Leading the research is Gemological Institute of America postdoctoral research fellow Evan Smith. The researchers are comparing diamonds with the largest ones found. Some of these large diamonds include the Cullinan, the Constellation and Koh-i-Noor. Through this study the researchers hope to know more about the Earth's mantle.
Dr. Wuyi Wang, the director of research and development at the Gemological Institute of America and a co-author of the study explained that large diamonds have different sets of characteristics from ordinary diamonds, though it is still not certain how exactly these diamonds have been formed. Some of the diamonds such as the Cullinan have metallic inclusions in them. Some even have mineral inclusions in them as well.
With the diamonds having such inclusions, it is likely that the large diamonds have been formed at depths that are far deeper, according to the GIA website. These depths are around 360-750 kilometers deep, which is much deeper than where most other diamonds are formed. A typical diamond would be formed at about 150-200 kilometers deep.
The metallic inclusions found in the large diamonds include iron, nickel, carbon and sulfur. Some trace elements such as methane and hydrogen can also be found, as Science Daily reports. Usually parts of a diamond that have such inclusions are taken off as they are deemed as imperfections. These parts are also not usually available for examination.
Through the study, Smith has said that looking into the large diamonds is evidence that the mantle at around 250 kilometers and deeper have traces of iron in it. The large diamonds also have methane and hydrogen which further supports the theory, he said. How much metal is in the mantle is still not certain.
The study though should provide more understanding about the inner Earth and how surface rocks are used up in the mantle. The large diamonds have been examined to know how the inner Earth works. Recently also a theory has been proposed how the Pangea breakup has thinned the Earth's crust.