Have you ever wondered where sand comes from? If the answer is yes, then you're in luck because we decided to do some digging, and sifted through the information to find an answer! (hehehe, we totally tried to get a sand pun happening)
Anyway...back to it!
We found the answer was very diverse and that sand is actually composed of different materials that vary depending on location. The location heavily influences the colour (sand comes an array of colours including white, black, green and pink!)
The most common component of sand is silicon dioxide in the form of quartz. Weathering processes — such as wind, rain and freezing/thawing cycles — break down these rocks and minerals into smaller grains.
Streams, rivers and wind transport quartz particles to the seashore, where the quartz accumulates as light-coloured beach sand.
Tropical islands, such as the Hawaiian Islands, don't have a rich source of quartz, so the sand is different in these types of locations.
The beach sand on tropical islands often looks white because it is made up of calcium carbonate, which comes from the shells and skeletons of reef-living marine organisms, including corals, mollusks and microorganisms called foraminifera.
Sand forms here when the reef breaks down, either by mechanical forces — such as waves and currents — or from bio-erosion caused by grazing fish, urchins and other marine life.
The famous pink sand of Bermuda is also composed of eroded calcium carbonate; the sand gets its ruddy hue from the abundant red foraminifera, Homotrema rubrum.
Tropical beaches may also have black sand, which is composed of black volcanic glass.
Sometimes, erosive forces separate the mineral olivine from other volcanic fragments, leading to green sand beaches, such as Hawaii's Papakōlea Beach.
Surprisingly little is known about the origin of the copious sand in the world's largest deserts. Research suggests that the Sahara Desert was once lush with vegetation before a change in climate turned it into a desert, part of which is covered in sand. On the other hand, the sand in the Namib Desert, in Namibia, may have been blown in by wind from the Orange River in South Africa.