Silica sand is one of the most common varieties of sand found in the world. The most common mineral in the Earth’s continental crust is quartz, and most silica sand is made up of broken down quartz crystals. Silica is another name for silicon dioxide, SiO2, of which quartz is a specific latticed structure. So silica sand is quartz that over the years, through the work of water and wind, has been broken down into tiny granules. These granules can be used for many different purposes, and can be found in most non-tropical regions of the world.