They are pure white sand rocks that contain a high percentage of SiO2 silica (more than 99%) mainly composed of quartz mineral granules and contain a small amount of impurities and heavy metals (less than 0.1%). As for the term glass sand, it is called silica sand (quartz), which has physical and chemical properties that are suitable for the glass industry, for example, the size of the granules, which usually ranges between 100 - 500 microns, and the percentage of iron oxides (Fe2O3) less than 0.05%. Silica sands are uncovered in several areas in southern Jordan, and these sands date back o the lower Ordevici and lower Cretaceous period.