Integrated XRF–XRD–Optical Characterization of Rock Samples from Leang Panning Park, Mallawa (Maros, South Sulawesi, Indonesia)

Abstract

This study characterizes two rock samples collected during a student field exploration at Leang Panning Park, Wanua Waru, Mallawa District, Maros (South Sulawesi) on 7–8 September 2023. Samples were prepared as polished bulk (~2 mm thick) for XRD and optical microscopy, and as powders for XRF. XRF shows that Sample A is dominated by Si (29.7 at%), with notable Al (7.65 at%) and minor Fe, Na, Ca, K, Mg; Sample B contains high Si (24.3 at%), Al (9.2 at%), Ca (8.21 at%), and Fe (7.07 at%). XRD phase identification indicates Sample A is albite-rich (~54–64%) with magnetite (~40%) and trace KO₂, SO₃, and Ba peroxide phases; Sample B is dominated by SiO₂ (46.5%) with sodium aluminum oxide (23.8%), magnetite (10.9%), K₂O (9.9%), and hydrated V₂O₅ (8.9%). Relative crystallinity from integrated peak areas is ~26.45% (A) and 15.77% (B), while Scherrer estimates give mean crystallite sizes of ~2.08 nm (A) and 6.21 nm (B). Results are consistent with silicate-dominated compositions and suggest igneous affinities discussed in the field report.