For must of us in the United States, beaches have always been synonymous with white sand. But in Morocco, some beaches are orange. There are red-colored beaches and there are black-colored beaches. Why are beaches so incredibly different around the world?

First, we have to understand what sand even is: Sand is basically rock and coral that has been ground up by violent crashing waves. This process can take thousands of years. And each grain of sand is incredibly tiny.

A sedimentary geologist explains it in more detail:

Interestingly, this beach in Hawaii is a shadowy-black color:

This beach is black because the sand was formed from volcanic rock, according to the University of Georgia Geology Department.

When oxidation occurs on some Hawaiian black-colored beaches, the sand basically turns into a rusty, red color, like this sample collected from Maui:



University of Georgia

And this is what sand from Bermuda looks like up close:



University of Georgia

This beach is white because it’s made-up of calcium carbonate (that’s the same stuff that our bones are made of). According to the University of Georgia, carbonate sands may be comprised of pulverized marine animals like snails, clam shells, starfish, algae, and coral.

Basically, this beautiful sand that you see here is comprised of millions of dead carcasses. The pink stuff you see is is an organism called Homotrema rubrum.

Here’s what some beaches in Morocco look like:



University of Georgia

This beach, near Casablanca, is comprised of mollusk shell fragments, which gives it an orange color.

Here’s sand in Antarctica:



University of Georgia

Notice how the sand pebbles are rocky in comparison to the fine sand that you see on beaches in California. That’s because beaches in glacial regions are younger, so the sand hasn’t had that much time to break down. The University of Georgia study also found that sands sampled in glacial regions have less quartz than other beaches (quartz is another material that gives sand its white color).

And this light-brown sand from Virginia’s Chesapeake Bay is probably what most of us are used to seeing:



University of Georgia

This sand is mostly comprised of quartz. But the white color was stained a sort of light brownish color when the the sand oxidized.