Sand reflects almost all facets of nature

Sand was probably also the first material ­encountered by marine organisms during their decisive first step toward land. Common only in the singular, sand is already a term for a multitude. About seventy of these are found in the preceding illustrations, completely detached from their context, i.e. removed from the sand as such. None of these individual particles is like the other. It is almost too absurd to imagine that there are probably no two completely identical grains of sand on earth. The discrepancy between the uniformity of the mass and the actual individuality of its components is particularly noteworthy when considering that, according to esti­mates, every single second on earth some 1 billion grains of sand are newly created by erosive processes.
What does it take for the grain of sand to become round?
Sand follows the laws of gravity. It is transported by water, ice or wind and deposited layer by layer from the ocean coasts across the edges of the continental shelves into the large ­basins of the deep sea. In this way, over millions of years, initially loose masses form kilometer-thick packs of layers, which are then gradually compacted and baked together. Entire mountain ­ranges, ablated by unstoppable erosion, are ­ultimately found in such sedimentary layers. The rocks newly formed in valleys in such a way are in turn displaced by ­processes of plate tectonics and folded up into mountains, where they again succumb to erosion and are worn away. The grain released from the sandstone on the mountain ridge is washed down to the valley, the cycle begins all over again. Cycle after cycle it would continue to round. According to rough estimates, each cycle could last about 200 million years. Small, very well rounded grains might have gone through up to seven cycles in this way with a total duration of 1.5 billion years or more.
The remaining question is, whether there are more grains of sand or stars?
No, over 85.7 quadrillion grains of sand on earth spans a sky with 70 trillion stars.