One. Scientific Foundations of Hollow Glass Microspheres 1.one Composition and Microstructure one.1.one Chemical Composition: Borosilicate Dominance Hollow glass microspheres (HGMs) are largely made up of borosilicate glass, a fabric renowned for its small thermal expansion coefficient and chemical inertness. The chemical make-up usually consists of silica (SiO₂, 50-ninety%), alumina ... https://www.geto.space/post/74062_elementary-substance-is-a-pure-chemical-substance-that-consists-of-atoms-belongi.html