Glass microbeads are essentially microscale marbles that look like white powder to the naked eye. A closer look with a microscope reveals their complicated particle geometry. The following images show a combination of two different types of particles. While some of the particles appear to have rounded edges, the rest of the particles appear to have razor sharp angular edges. Without a microscope, these conclusions are unavailable to any observer.
These glass beads are commonly used in polymers and cementitious materials as fillers to reduce the cost of materials. Glass beads also improve the mechanical properties of some thermoplastic polymers.