Core Viewpoint - The impurities in natural quartz are influenced by geological environmental factors, including the nature of the melt or fluid during quartz crystallization, diagenesis, and subsequent changes. Group 1: Aluminum Element - Aluminum can crystallize in two forms in igneous rocks, affecting its incorporation into the quartz lattice, with [AlO4]5– replacing Si–O tetrahedra under certain conditions [3] - The presence of aluminum in quartz is primarily determined by the geological environment, which can limit the formation of [AlO4]5– and reduce aluminum content [3] - The crystallization of quartz is influenced by the strength of covalent bonds, which affects the incorporation of aluminum impurities [3][5] Group 2: Titanium Element - Titanium exists mainly in the Ti4+ state and can replace Si4+ in the quartz lattice, with its abundance being temperature-dependent [7] - The concentration of titanium in quartz decreases with lower temperatures, indicating that temperature is a critical factor for titanium distribution [7] - The growth rate of quartz crystals is positively correlated with the concentration of titanium impurities [7] Group 3: Germanium Element - Germanium can substitute for Si4+ in the quartz lattice and its abundance is also influenced by temperature, with higher concentrations at lower temperatures [8] - The presence of germanium in quartz is independent of other elements like Li, K, and Ga, suggesting a unique mechanism for its incorporation [8] - Similar to aluminum and titanium, the concentration of germanium in quartz is affected by the geological temperature conditions [8]