A physico-chemical analysis is performed of technologies for producing quartz grit and making glass from it. Experimental production of glass from grit was performed. The conditions of melting made it possible to form microgranular inhomogeneity with a volumetric network of boundaries in a glass ingot decorated with impurities. Optical, electron microscopic, and mass spectroscopic studies confirm the new hypothesis of microgranular heterogeneity appearing in quartz glass. The results of these studies can be taken into account when making high-quality ultrapure quartz glass for science-intensive industries.