Alum crystals. Alum is the term given to crystallized double sulphates. They are soluble in water, have an astringent, acidic taste and crystallize in regular octahedrons. Alum is used in dyeing. Editorial Stock Photo - Afloimages
Alum crystals. Alum is the term given to crystallized double sulphates. They are soluble in water, have an astringent, acidic taste and crystallize in regular octahedrons. Alum is used in dyeing.