Mineralogically relevant chalcogenide glasses with the composition Cu x Bi 5 Ag 5 (As 0.33 S 0.335 Se 0.335 ) 90-x (x=2, 6, and 10, in mol%) that approximate the chemistry of some unusual sulfide mineral assemblages were synthesized. The differential thermal analyses revealed that the glass transition temperature (T g ), onset crystallization temperature (T c ), and peak temperature of crystallization (T p ) first increase significantly with an increasing Cu content from 2 to 6 mol%, and then remain almost constant when the Cu content further increases to 10 mol%; the glass thermal stability also increases with an increasing Cu content. Both dry annealing and hydrothermal treatments were carried out in the temperature range of 207°-331°C for up to 96 h. X-ray diffraction analyses on annealed samples showed that dry annealing and hydrothermal treatments produced different phase assemblages. Dry annealing produced crystallized phases AgBiSe 2 (bohdanowiczite), Cu 2 Se (berzelianite), Ag 3 AsS 3 (xanconthite), Cu 3 AsS 4 (luzonite), AgBi 3 S 5 , and As 4 CuS 9 , while hydrothermal treatments produced phases AgBiSe 2 (bohdanowiczite), AgBi 3 S 5 , and AgAsSe 2 . This case study presents a new way for studying the formation and alteration of minerals in nature.