The Relationship of Mineral Composition to the Mechanical Properties of Rocks in Loli Saluran Area Donggala District Central Sulawesi Province

Muslimin U. Botjing (Geological Engineering Study Program, Civil Engineering Department, Engineering Faculty, Tadulako University)
Bey Nida’ul Hasanah (Geological Engineering Study Program, Civil Engineering Department, Engineering Faculty, Tadulako University)
Nunik Rezkiarti Janat (Geological Engineering Study Program, Civil Engineering Department, Engineering Faculty, Tadulako University)

Formosa Journal of Science and Technology (FJST)
Vol. 5 No. 8 (2026): August 2026

This study was conducted in the Loli Saluran area, Donggala District, Central Sulawesi Province, located within the Tinombo Formation and dominated by andesite. Rock quality can be assessed through mechanical properties controlled by mineral composition. This study examines the relationship between mineral composition and compressive strength, Young’s modulus, and Poisson’s ratio using X-Ray Diffraction, Uniaxial Compressive Strength, petrography, regression, and correlation analyses. Three samples were tested to represent eleven data points. Petrographic analysis identified porphyritic meta-andesite and diorite composed mainly of plagioclase, quartz, and chlorite. Correlation results show that plagioclase has a very strong positive relationship with mechanical properties, whereas quartz and chlorite have very strong negative relationships. Thus, mineral composition reflects rock mechanical properties and can indicate rock quality