A Portable Gamma Ray Spectrometer can analyze a wide range of geological materials. It is particularly effective in identifying and quantifying the natural radioactivity in rocks and sediments, focusing on elements like potassium, thorium, and uranium. These elements are prevalent in various rock types, and their presence can indicate the composition and quality of the geological formations. This analysis is essential for assessing the porosity and permeability of rocks, crucial for determining reservoir quality in the oil and gas sector.