The most common method used for gold processing in artisanal and small-scale mining is amalgamation using mercury as a gold extracting agent. Indonesia is one of the countries that ratify the Minamata Convention, meaning that Indonesia has agreed to reduce or even eliminate the use of mercury. Some methods for replacing mercury as a gold-extracting agent are cyanidation and borax. The research aims to determine whether the miners in Pelangan still use mercury in gold processing. The method of this research is observation, interviews, and literature review. The data obtained were then analyzed descriptively. The result indicates that the miners in Pelangan Village use two methods of gold processing from ore: (1) amalgamation using mercury followed by cyanidation and (2) cyanidation. Most of the miners use the cyanidation method without going through amalgamation. The main reason they do not use mercury are amalgamation method yields low gold recovery and the price of mercury is high. This indirectly shows that the miners in Pelangan Village have contributed to efforts to reduce mercury use in Indonesia.

West Nusa Tenggara Province has the potential of natural resources such as marble, calcite, limestone, manganese and gold. The research area consists of limestone, which is included in the Ekas Formation which is based on the Geological Map of Lombok. One of the mineral resources available in the study area is material limestone in Mangkung Village, West Praya District, Central Lombok Regency. With the potential for minerals, it is necessary to do a reserve calculation to find out the range of the amount of material limestone quarry in Mangkung Village. The purpose of this research is to find out the amount of limestone resources in Mangkung Village. This study focus on quantitative mapping of limestone, widely used for natural building stone, sources of water for urban and agricultural development in Mangkung village, Western Praya. This research applied the cross-section method to calculate limestone deposits in study area. This cross-section method divides the study area into several cross-sections with a distance of 25 meters each. The calculating result shows the volumetric of limestone reserves in Mangkung Village is about 73,874.42 m3. For the weight calculation, this research uses average density of limestone of about 2.38 ton/m3, and we found a total weight of limestone in Mangkung village is about 176,338.25 tons.