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,
ARIA Award for Best Rock Album ARIA Award for Best Rock Album The ARIA Music Award for Best Rock Album, is an award presented at the annual ARIA Music Awards, which recognises "the many achievements of Aussie artists across all music genres", since 1987. It is handed out by the Australian Recording Industry Association (ARIA), an organisation whose aim is "to advance the interests of the Australian record industry." To be eligible, the recording must be an album in the contemporary rock, modern rock and active rock formats, and cannot be entered in other genre categories. The accolade is voted for by the ARIA Judging Academy,