This study conducts on drill-core samples from the Gossan Hills Tenement, Andong Meas Prospect, Ratanakiri Province, Cambodia, an area fully potential of metallic and none metallic resources. The primary objective was to classify the mineralogy, thoroughly investigate the intricate processes of hydrothermal alteration, and precisely identify the associated ore mineralization, thereby confirming the presence and characteristics of a polymetallic replacement and copper-iron-zinc deposit. Samples from three drill holes (CW21-007D, 008D, and 009D) were analyzed using Petrography Analysis and Ore Microscopic Analysis. The drill logs confirm the presence of intrusive rocks, diorite and granodiorite (the inferred heat source), and extensive andesite (the host rock). Petrographic analysis, identified diagnostic minerals such as quartz, biotite, pyroxene, both of primary and/or secondary k-feldspar and calcite, plagioclase, amphibole, andradite, actinolite, and epidote, alongside chlorite, which directly correspond to the expected mineralogy. The observed zonation, from prograde andradite-rich assemblages to retrograde epidote-chlorite-sulfide associations, aligns with established metallogenic models. Crucially, the ore mineral suite, including chalcopyrite (Cu), sphalerite (Zn), galena (Pb), pyrite, covellite, and magnetite, perfectly matches the polymetallic (Cu-Fe-Zn) characteristics of this deposit type. This comprehensive evidence definitively confirms the application of the polymetallic replacement and Cu-Fe-Zn skarn deposit model to the Gossan Hills tenement.