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,
Buffalo Head Hills kimberlite field in mudstones that are interbedded with some of the kimberlite deposits are consistent with the Late Cretaceous age. The BHH kimberlite pipes cover areas ranging from one to . They represent maar-style volcanoes which have a vertical-walled volcanic crater of explosive origin, surrounded by a low rim of ejecta and filled with water. Pyroclastic fall and surge are the two volcanic mechanisms of deposition. There are also deposits formed by hydraulic reworking of kimberlite from tephra cones and/or extra-crater fall and surge deposits. The pyroclastic fall deposits are poorly sorted and massive, while the surge deposits are better sorted, fine