Group 1 - The significance of high-purity quartz lies in its applications across various industries such as semiconductors, high-temperature lamps, telecommunications, optics, solar silicon, and microelectronics, with a quality standard set at SiO2 ≥ 99.9 wt.% [1][3] - The rapid development of markets in semiconductors, optical communications, and photovoltaics has led to a relative scarcity of high-purity quartz resources, prompting evaluations of quartz raw materials for economic value and efficient resource utilization [3][4] - Hydrothermal quartz, characterized by large crystal grain sizes and high SiO2 content, is identified as an ideal raw material for high-purity quartz processing, potentially replacing natural crystals [3][4] Group 2 - The four quartz samples from Laos, Zimbabwe, South Africa, and Pakistan exhibit varying degrees of transparency and are all coarse-grained with an oily luster, lacking visible accompanying minerals [2][3] - The presence and type of inclusions in quartz crystals significantly affect the quality of high-purity quartz sand, with fine mineral inclusions making processing more challenging [4][5] - The samples from Laos and Zimbabwe show minimal inclusions, while those from South Africa and Pakistan have more developed inclusions, although some grains remain clean [5][6] Group 3 - Purification experiments on the four quartz samples involved multiple processes, resulting in quartz sands with SiO2 content reaching approximately 99.99 wt.%, with specific impurity levels detailed in a table [6][7] - The purified quartz sands primarily contain impurities such as Li, Al, Ca, and Ti, with the highest SiO2 content recorded at 99.992 wt.% for the Laos sample and the lowest at 99.989 wt.% for the Zimbabwe sample [7][8] Group 4 - Microscopic observations of the purified quartz sands reveal fewer inclusions, indicating a higher purity level, although some samples still retain certain inclusions that may contribute to impurity elements [8][10] - The main components of the fluid inclusions in the quartz samples are CO2 and H2O, which are easier to remove during processing, leading to a cleaner final product [11]