The environmental impact of Merelani mines can be attributed mostly to the simple technology and the lack of technical know- how of most miners. The tools and extraction methods employed by small-scale miners are very basic. The rudimentary technology employed usually results in low rates of recovery that in turn leads to poor earnings and an inability of most miners to invest in appropriate technology. These results in a poor market, returns, working conditions, and a vicious cycle, which most miners find difficult to break. The mode of operation affects their ability and willingness to invest in proper mining methods. During the period of 1996-2002, a total of 17 people lost their lives due to collapse of hanging walls and 7 deaths caused by falling into a shaft, 3 deaths due to mine waste slide. The main cause was poor unplanned mining methods.

Land degradation

Most of the tanzanite mining activities are carried out underground, through deep shafts. As single licensed claim of 50x50 m is divided into small plots. During both shaft development and mining, a substantial amount of waste is excavated and piled in the vicinity of each shaft. The excavated shafts and piles of waste rock left behind after mining ceases have been identified as a severe, but localized, land degradation, which results in mine disasters e.g. flooding in wet season. In 1998, most mines in block B were flooded claiming more than 71 live