To understand the significance of diamond indicator minerals, one must first understand how diamonds surface to the earth. Through volcanic eruptions that occur deep inside the earth, certain diamond-bearing rocks are pushed close to the surface of the earth. These rocks are either kimberlites or lamproites — igneous rocks that have cooled upon reaching the earth’s surface. Magma pushes these rocks from deep within the earth to its surface. After diamonds have been deposited in the earth’s surface they may spread over a large area. There are primary and secondary sources of diamonds. Primary sources are volcanic pipes containing diamonds, while secondary sources are the other areas where there are significant numbers of diamonds. To search for diamonds, experts look for certain indicator minerals that tell that the area is rich in diamonds.
A number of minerals are present in these diamond-bearing rocks that are known as indicator minerals for diamonds. These indicator minerals are more abundant than diamond. That is why geologists and other explorers look for them in areas which they suspect are rich in diamonds.
The accuracy of indicator minerals in telling the presence of diamonds depends on the type of mineral. Some minerals provide greater accuracy than others. Of course, the presence of diamonds is a clear indicator that there are other diamonds in the area. Garnet, chromite and Limonite are three minerals that indicate rich diamond loads. Garnet is a mineral that is also used as gemstone and is quite precious. It is usually red in color but also comes different colors. Chromite is an oxide mineral that belongs to the spinel. Other minerals that experts look out for when searching for diamonds include clinopyroxene, olivine, and zircon. An abundant presence of two or more of these minerals in an area almost always is indicative that there is diamond there.
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October 23rd, 2008 at 3:59 am
Very nicely explained in easy way.