(April 2015) Corruption in Brazil exists on all levels of society from the top echelons of political power (as seen in the MensalÃ£o Scandal and the Operation Car Wash and the Petrobras scandals) to the smallest municipalities.
Quartz sands, which are high in silica content, are used to make glass. When quartz sands are crushed they produce particles with sharp, angular edges that are sometimes used to make sandpaper for smoothing wood. Some quartz sand is found in the form of sandstone.
Before glass, homes must either have been very dark but warm, or light but cold. Smashing Stuff. Glass is sand thatâs been heated to a very high temperature. Obsidian is a natural glass, made by volcanic eruptions millions of years ago. Lightning strikes on sand also produce natural glass, called fulgarites.