Kimberlite garnets rich in chromium, are generally absent from most other igneous rocks, making them particularly useful as indicators for kimberlites. These indicator minerals are generally sought in stream sediments in modern alluvial material. Their presence may indicate the presence of a kimberlite within the erosional watershed that produced the alluvium. The geochemistry of Kimberlites is defined by the following parameters: Kimberlites are the most important source of primary diamonds. Many kimberlite pipes also produce rich alluvial or eluvial diamond placer deposits. About 6,400 kimberlite pipes have been discovered in the world, of those about 900 have been classified as diamondiferous,
Grammy Award for Best Rock Performance Recording Academy's wish to decrease the list of categories and awards and to eliminate the distinctions between solo and duo/groups performances. The Academy argued that any distinction between these performances is difficult to make, as "four-fifths of rock acts are groups, and even solo rock acts tend to be backed by a band". From 2014, this category has also included hard rock performances that were previously screened in the Best Hard Rock Performance and Best Hard Rock/Metal Performance categories, which are now defunct. Grammy Award for Best Rock Performance The Grammy Award for Best Rock Performance is an award presented