This paper presents a comprehensive and in-depth study on the particle breakage behavior within a miniature specimen of highly decomposed granite subject to one dimensional compression with in-situ X-ray micro-tomography. Based on a successful full-field particle tracking analysis of almost all broken and unbroken particles which is enabled by a powerful particle tracking technique called SHOT++, we revealed a wide range of particle-scale phenomena and processes associated with particle breakage including evolutions of particle size, number, shape, specific surface and fractal dimension. SHOT++, which is formed by integrating the Iterative Closest Point algorithm and the Random Sample Consensus algorithm into the Signature of Histograms of Orientation (SHOT) algorithm, firstly distinguishes the original surfaces of a broken particle from its fracture surfaces, and then encodes its morphological information using the three-dimensional SHOT descriptor, and finally determines the optimal match and the transformation matrix to its original particle. The high tracking accuracy of SHOT++ allows it to track the movements of the majority of all broken and unbroken particles throughout the test and thus to reveal unprecedented insights into the microscopic mechanisms underlying the macroscopic compression behavior of HDG.