Evaluation of serpentinite composition through X-Ray fluorescence and complementary analytical methods

¹ National Institute for Research and Development in Mine Safety and Protection to Explosion – INSEMEX Petroșani, 32-34 General Vasile Milea Street, Petroșani, Romania
² University of Petroșani, 20 University Street, Petroșani, Romania
³ Carmen Sylva National Informatics College, 10 Slătinioara Street, Petroșani, Romania

^* Corresponding author: sonia.suvar@insemex.ro

Abstract

Serpentinite, metamorphic rocks primarily composed of serpentine-group minerals, pose significant challenges in chemical analysis due to their complex and heterogeneous composition. The variability in mineralogy, including the presence of resistant phases such as chromite and magnetite, complicates sample dissolution and leads to potential inaccuracies in bulk chemical data. Additionally, the high content of structurally bound water in serpentine minerals interferes with gravimetric and thermal analyses, while the presence of elements in multiple oxidation states, such as Fe²⁺ and Fe³⁺, requires specialized analytical techniques. In this study, we present results from X-ray fluorescence spectroscopy (XRF) analyses conducted on serpentinite samples. XRF offers a non-destructive approach for determining major and some trace elements without requiring acid digestion, making it suitable for routine geochemical screening. However, to overcome the limitations inherent to each method, XRF data are complemented by other techniques, including inductively coupled plasma mass spectrometry (ICP-MS), thermogravimetric analysis (TGA), and alkali fusion or acid digestion protocols. This integrated approach enhances the reliability of the compositional data and supports more accurate interpretation in geological, mineralogical, and environmental studies involving serpentinites.