human
How many different types of sand are there on Earth?
assistant
There are at least three main types of sand on Earth. The first is quartz sand, which is made up of quartz crystals and has a smooth texture. The second type of sand is composed of crushed shells, such as seashells or riverbed stones. This type of sand is usually gritty and has a rough texture. The third type of sand is made up of minerals that have been weathered from rocks, such as feldspar sand. Feldspar sand is usually light-colored and has a smooth texture.