RE: Boart - whoops, correction"Diamonds are sent from the mine to Yellowknife for cleaning and preparation for valuation before being exported from Canada. Approximately 80 percent of total production is of gem quality."
"Indeed, the now-famous A154S pipe is thought to be the richest in the world. It yields an average of 4.8 carats per ton, a large proportion of which are high quality gems, and now forms part of the Diavik mine"