Buffalo Head Hills kimberlite field They have a low carbonate content, low abundances of late-stage minerals such as phlogopite and ilmenite, and a high abundance of fresh, coarse olivine. Based on examination of more than 700 examples, the BHH diamonds range in color from colorless to yellow and brown, and most are transparent and colorless. The majority are sharp-edged octahedra, but ~45% were dodecahedral due to resorption of octahedra. Inclusions of garnet, olivine, clinopyroxene and rutile were found in a few specimens. Buffalo Head Hills kimberlite field The Buffalo Head Hills kimberlite field is a group of kimberlitic volcanic pipes or diatremes in north-central Alberta,
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