Fig. 1

Microscope images of some of the used quartz configurations. (A) uniform glass spheres, (B) elliptical and round glass beads, (C) glass beads of varied sizes and shapes, (D) natural quartz sand, and (E) crushed glass.

Microscope images of some of the used quartz configurations. (A) uniform glass spheres, (B) elliptical and round glass beads, (C) glass beads of varied sizes and shapes, (D) natural quartz sand, and (E) crushed glass.