There is sand on every sea beach: Ever wondered why?

You must have visited a lot of beaches during your vacations. You probably have built sandcastles there, doodled your name and even taken a stroll with your parents barefoot on the beach. But have you ever wondered where the sand comes from? Let’s find out.  

Beautiful beaches and how their sand is formed 
'There is history of the Earth in every curving beach and in every grain of sand,' said environmentalist Rachel Carson. What he meant was that the sand found on beaches worldwide results from the weathering of rocks over millions of years and the deposition of coral fragments by waves. Sand is a naturally granular substance and comprises tiny, extremely fine rock and mineral particles. The term ‘sand grain’ refers to a single sand particle. The size of a sand grain is between 0.0625 and 2 millimetres! Quite tiny, right? Silica (silicon dioxide, SiO₂), typically found in quartz, is the most prevalent component of sand found in inland areas. Calcium carbonate, which has accumulated through millions of years, is another most common component of sand. 

Why are there so many sandy beaches? 
The minerals quartz and feldspar create the majority of sand you see on the beach worldwide. These minerals are created by the weathering and erosion of igneous and metamorphic rocks over millions of years. While some minerals are brittle and break down easily, others are more enduring and less likely to erode. Therefore, the weathering of rocks over millions of years is one reason that so much sand gets up on beaches. This phenomenon is also observed with rivers in motion. They constantly erode the surrounding terrain, reducing boulders to sand-sized fragments. 

The mystery behind colourful beaches 
You’ve probably seen how beaches in Iceland are famous for their black sand. But did you ever wonder why sand on beaches in India or many other countries are brown or white? This is because the eroded rocks and the local geological circumstances determine the colour of the sand. Iron oxide, which gives quartz a light brown tint, and feldspar, which is brown to tan in its native state, are responsible for the tan colour of sand seen on most beaches. The black sand you see is generally found on beaches close to volcanic activity and is made of eroded volcanic material like lava, basalt rocks and other dark rocks and minerals. Now you know why Iceland, Hawaii, the Canary Islands and the Aleutian Islands have numerous black-sand beaches, right? 

The production of sandy beaches is also significantly influenced by the by-products of living creatures. Bermuda has an abundance of pink beaches that amaze us. The pink sand is a product of foraminifera, single-celled, shelled creatures that continually decompose. Hawaii’s famous white sand beaches are formed from parrotfish waste (the coral skeleton is white because it is formed of calcium carbonate). Parrotfish may generate hundreds of pounds of white sand a year while preserving a rich coral-reef habitat! Similarly, the olive-green mineral olivine, which is present in large quantities in basalt in some regions of the world, is thought to be responsible for the green hue of some beaches.