The document describes different mineral groups found in hydrothermal systems based on temperature and pH conditions. It includes groups such as the silica group found under low temperature, non-dissociating conditions. The alunite group is found under slightly higher temperatures. Higher temperature groups include the illite-kaolinite, chlorite, and illite groups. The document also describes mineral associations related to different deposit types including porphyry, epithermal, skarn, and mesothermal systems.