Abstract
Illegal extraction of gold has grown to be a problem in many countries, causing the degradation of the environment. The main purpose of this paper is to investigate changes in tree cover and surface pollution. The development of a mine site has been observed and analysed with images acquired from Landsat and the Sentinel missions. The results of the study showed changes in the state of the environment, strongly suggesting the possibility of ongoing pyrite weathering processes and the transportation of clay materials down watercourses, which can cause not only the further deterioration of the environment but also slow down the natural regeneration of the forest. In addition, research has found disturbing changes in vegetation, showing a loss of tree cover in the Amazon Rainforest as high as 17%. The validity of using remote sensing methods to observe the development of individual mining sites and their characteristics was confirmed.