At present, there are some fake hollow glass microspheres on the domestic market. Expanded perlite, often used in the manufacture of refractories, has a confusing trade name: vitrified beads. But they are not really ones. Pearlite has a popcorn-like structure. Its inner voids are interlinked, easy to absorb moisture, and very weak, only in special circumstances. For example, high temperature drying has a certain insulation function. There is also a kind of fly ash hollow beads, also known as drifters, which are extracted from the fly ash of thermal power plants. Although they are hollow structures, they are not completely spherical. Most of them are open and porous structures. Internal air can flow freely, insulation performance is poor with high density,  which do not have liquidity, either. The production technology of hollow glass microspheres has been monopolized by the United States, Japan and Russia for a long time. Among them, Japan and Russia only supply their own products, and no civilian products are sold or exported. Some domestic manufacturers create bleach and other fake products impersonate hollow glass microspheres in long-term.