information:filtering, structural:summarization, structural:reformatting, quality:corruption
Double salts

Double salts containing magnesium sulfate exist. There are several known as sodium magnesium sulfates and potassium magnesium sulfates. A mixed copper -magnesium sulfate heptahydrate (Mg,Cu)SO · 7H O was found to occur in mine tailings and was given the mineral name alpersite.