No one is certain exactly how much unearthed tanzanite still remains, as data has not been collected from the several hundred small mine sites situated in D & B blocks. These smaller sites are currently mined using very simple methods and basic air supply systems, and don’t have the ability to dig any further without significant investment and the purchase of mechanized mining equipment. Thus, their ability to dig much deeper is restricted, as is further information about the deposit.

When tanzanite is gone, the stone could become a historic “heritage” stone that is desperately sought after by collectors across the globe. But when this will be, no one is sure.