Diamond (gemstone) be considered appropriate for use as a gemstone; the other 80% are relegated to industrial use. Of that top 20%, a significant portion contains one or more visible inclusions. Those that do not have a visible inclusion are known as "eye-clean" and are preferred by most buyers, although visible inclusions can sometimes be hidden under the setting in a piece of jewelry. Most inclusions present in gem-quality diamonds do not affect the diamonds' performance or structural integrity. When set in jewelry, it may also be possible to hide certain inclusion behind mounting hardware such as prongs in a way that
Buffalo Head Hills kimberlite field kimberlite province, along with the Birch Mountains kimberlite field and the Mountain Lake cluster. It is located about north of the city of Edmonton in the Buffalo Head Hills of northern Alberta. The area lies within the Canadian boreal forest and is sparsely settled. Access is via Alberta Highway 88. Deep beneath the BHH kimberlite field lies a 2.0 to 2.4 billion year old Precambrian craton called the Buffalo Head Terrane, which has no exposure at surface. The Precambrian craton is overlain by about of Paleozoic and Mesozoic sedimentary rocks, which are covered by as much as of unconsolidated glacial