Quartz

Quartz is the most important sand-forming mineral and occurs in very many sand types but usually not exclusively. In this sand type (which is aptly named quartz sand). 

Quartz is almost the sole component of sand. Similar sandstones are called quartz arenites or orthoquartzites.

Quartz is the most important sand-forming mineral because it is resistant to both physical and chemical weathering. Sand that is enriched in quartz is likely old (mature) and has traveled far from the source area, sometimes thousands of kilometers. Long journey is required to allow weathering to break down weaker minerals that were initially present in the rocks.