human
How many different types of sand are there on Earth?
assistant
There are three main types of sand on Earth. These are quartz sand, feldspar sand, and mica-schist sand. Quartz sand is the most common type of sand, accounting for about 70% of all sand on Earth. Feldspar sand accounts for about 15% of all sand on Earth, and mica-schist sand accounts for about 15%.