Typically, people think of white sand when they think about the ideal beach. However, not every beach has coconut trees, volleyball games, and pristine, white sand. There's a black sand beach in Iceland, and some of the sand in Hawaii can turn red. So, how does one explain these differences?
For now, what we should understand is the basic fact about sand: it's primarily composed of coral and rock which have been barraged again and again by strong waves crashing down onto them. Thus, each grain of sand -- measuring less than an inch -- is the outcome of a natural activity that can take thousands of years.
Research by the Geology Department of the University of Georgia declared that the sand here is black because it originally came from volcanic rock.
Likewise, the black sand can change its color. As seen from this sample, they can turn into a red, albeit, rusty color once they undergo the process of oxidation.
Here, the sand is mostly white because it's composed of calcium carbonate; that's right -- the same material our bones have. Yep, gorgeous white sand is made up of dead organisms. Thus, these sands are actually a collection of grounded marine animals, such as starfish, snails, and clam shells -- all combined with coral and algae.
Orange sand, like this one found near Casablanca, consists of fragments of molusk shells.
The first thing you would notice about sand from Antarctica is how they are relatively larger than the previous one we've seen. The next observation is that it is not white. The beaches located in glacial regions are actually much younger than those in tropical areas, meaning they haven't experienced the same barrage of crashing waves to pulverize them further. In addition, white isn't apparent here because of the lack of the mineral quartz.
Light-brown -- this is the sand color we are most familiar with. Mostly made up of quartz, the reason why it isn't white is the same as why the black sand in Maui turned rusty red -- through oxidation.