Here's why:

* Sand: Sand is primarily composed of silicon dioxide (SiO2), which is the chemical compound that makes up the mineral quartz. Quartz is one of the most common minerals on Earth.

* Rock: While rocks can be made of various minerals, many rocks, especially those found in sandy areas, contain silica (silicon dioxide). This includes sedimentary rocks like sandstone, which is formed from cemented sand grains.

* Soil: Soil is a complex mixture of mineral particles, organic matter, water, and air. The mineral particles in soil come from weathered rock, and silicon is a major component of many of these minerals.

While silicon is the most prominent element, other elements are also found in sand, rock, and soil in varying amounts, including oxygen, aluminum, iron, calcium, and potassium.