Study of pyrite mineral type in sorong coal based on petrographic analysis

Abstract The research site is located in the Inamo area of Sorong Regency. The research area is situated in the western part of Papua Island, administratively belonging to Southwest Papua Province. The objective of this study is to examine the type of pyrite minerals in Sorong coal based on petrographic analysis. The research methodology employed to achieve the research objective includes field geological surveys and laboratory petrographic analysis. The research results and discussion indicate that the geomorphological unit of the study area is the Alluvial Plain Unit. The lithological unit of the research area consists of alluvial deposits containing layers of coal and mudstone. Petrographic analysis of the Sorong coal reveals that the pyrite type is syn-genetic, as the pyrite crystals under the microscope exhibit euhedral and massive forms. Euhedral pyrite can be recognized as well-formed pyrite crystals. The majority of euhedral pyrite is syn-genetic and formed during peat deposition and/or early humification. On the other hand, massive pyrite is usually found as filling in fractures/cavities, cementation, or framboidal mantles, either euhedral or detrital minerals.