Grain of Sand (Medium)

One of roughly 7.5 quintillion on Earth/Scientific Objects

A medium grain of sand is about 0.5 mm in diameter and weighs approximately 0.044 milligrams. It is mostly silicon dioxide (quartz) and was likely once part of a larger rock that was broken down by millions of years of weathering. There are estimated to be 7.5 x 10^18 grains of sand on Earth. Remarkably, there are more stars in the observable universe than grains of sand on all of Earth's beaches.