HabitEst3D: A User-Friendly Software for Estimating Mixed Crystal Habits from Two-Dimensional Sections in Igneous Rocks

Abstract

Crystal habit in igneous rocks provides a window to understand magmatic processes or reveal crystallization environments. Generally, we can obtain the two-dimensional (2D) crystal habits directly from the thin section, which is easy to access. However, the three-dimensional (3D) habit cannot be directly observed in thin sections and needs the stereological conversion from 2D habits. Statistical methods have been developed for stereological conversion, but they cannot identify mixed habits. Our study uses the distributions of the cut-sections of pre-set habits to match the unknown sample and enumerates habit combinations to find the best-match results for mixed habits. The specialized program, HabitEst3D, is developed according to our model in this study. The program is written in Python and is a cross-platform with a user-friendly graphical interface. The input data are the aspect ratio of 2D sections. After setting the parameters, the program finds the best-match estimations fitting the sample, visualizes the results, and saves them in multiple file formats. The program is robust and is not sensitive to outliers to obtain more accurate results. It traverses all possible combinations and needs memory and time but effectively explores the mixed crystal habits in the sample, contributing to investigating magmatic processes in more detail.