Colored Sand Beaches—What Gives Sand Its Color?
Who doesn’t love a nice, relaxing day at the beach? But have ever wondered where does the sand color come from? And why are there so many different sand colors? If you want to learn what gives sand its color, and where to find beautifully colored beaches, keep on reading.
A few years ago I went on a holiday to the island of Bermuda in the Atlantic Ocean. There, I spent some time at this really beautiful pink sand beach in the Horseshoe Bay. That pink sand, plus the most amazing turquoise water I’ve ever seen, inspired a location in my first novel—a pink sand beach on an alien planet.
Seeing that pink sand beach in Bermuda got me curious as to why was the sand pink. And when researching the sand color, I found a large variety of colored sand beaches around the world. These vary from white sand beaches all the way to black sand beaches.
So let’s explore them together and learn what gives sand its color. We’ll go from light colored sand to dark-colored sand, and in the end, I have two bonuses on multicolored sand beaches.
What is sand?
Sand is a granular material composed of very small particles whose dimensions can range anywhere between 0.0625 mm and 2 mm. Its composition varies depending on the location and the composition of the rock sources, but its most common component is quartz. Quartz is a silica mineral, it is silicon dioxide (SiO2).
Sand is produced through a weathering process of rocks and minerals. Some of these natural weathering processes include rain, wind, and ocean currents, as well as freezing-thawing cycles. Since the weathering processes do not affect quartz, this mineral remains in its small granular form and it is then transported to the shore, forming the sand we see at the beach. And the reason for the usual overall yellowish color of the sand is the presence of impurities in the quartz crystal or the mixing of quartz particles with other particles. However, not all beaches are made up of sand rich in quartz. We will see what other main components are present in sand as we go through the different sand colors.
So let’s start exploring the colored beaches around the world, going from light-colored sands to the dark-colored sands.
White sand beaches
As I mentioned earlier, sand is made up of quartz. But usually, quartz also contains impurities or is mixed with other particles, giving the sand the yellowish color. However, when the quartz grains are pure and not mixed with other particles, we get a white-colored sand. And that’s the case of the Hyams Beach in New South Wales, in Australia. Its finely ground pure quartz crystals is what makes the sand of this beach so white that it got into the Guiness Book of Records as the whitest sand beach.
Other white sand beaches include the Matira Beach in bora Bora, French Polynesia, Boulders Beach in Cape Town, South Africa, and Tulum Beach in Mexico.
Pink sand beaches
The pink color of the sand comes from tiny organisms called foraminifera. They are single-cell organisms which build shells around themselves from the minerals they find in the water. Usually, these shells are made of calcium carbonate, with the shell color ranging from pink to red. When the foraminifera organisms die, the remains of their shells are washed to shore. By mixing these pink-to-red foraminifera shell remains with the quartz particle we get the beautiful pink sand that we can admire in the Horseshoe Bay Beach in Bermuda, or the Pink Sand Beach on Harbour Island in Bahamas, Elafonissi on the island of Crete in Greece, Tangsi Beach on Lombok Island in Indonesia, and many other places around the world.
Orange sand beaches
When the sand contains minerals that are rich in iron, the sand gets an orange color. In the calcium carbonate- based sands, the calcium carbonate came from the weathering of rocks made of limestone. If there were traces of iron present in the limestone, then those iron impurities mixed with the calcium carbonate, crushed shells, and volcanic deposits will produce an orange-colored sand. We find orange sand beaches in Ramla Bay in Gozo, Malta, in Porto Covo in Portugal, and Porto Ferro in Sardinia.
Red sand beaches
There are many volcanic beaches around the world created by the past and present eruption of volcanoes. When the lava from the volcanic eruption cools down, it solidifies, forming the volcanic rock. If this happens above the surface of the ocean, the iron from the lava rock reacts with the oxygen from the air forming iron oxide, or what we commonly refer to as rust. We’ve seen previously that sand forms through different weathering process of the rock. Through the weathering of this iron oxide-rich volcanic rocks, the rock is ground into the red sand particles that give the color red to the red sand beaches. Red sand beaches are found in volcanic regions, such as the Kaihalulu Beach in Maui, Hawaii, Rabida Island in Galapagos, Ecuador, and Cavendish Beach on Prince Edward Island in Canada.
Purple sand beaches
At the purple sand beaches, the quartz grains are mixed with particles coming from the erosion of rocks from the nearby hills that contain the manganese garnet mineral. The rain washes down these manganese garnet particles to the shore, mixing them with the quartz grains on the beach. This creates patches of purple-looking sand where the two types of sand particles mix. The heavier the rain, the more abundant the purple areas of sand. This is what we see at the Pfeiffer Beach in California.
But we also find purple beaches in other areas, where the color purple comes from mixing a variety of sand grains with different colors. These include grains of pink almandine-pyrope garnet, white quartz, a mix of black minerals, including augite, ilmenite and hematite, and green epidote. All these particles together create the purple sand at the Plum Island Beach in the state of Massachusetts in the US.
Green sand beaches
When the lava from volcanic eruptions is rich in a mineral called olivine, upon cooling of the lava, the olivine crystals are formed. As they separate from the lava and accumulate on the beach, these particles are the ones responsible for the rare green colored sand beaches. Examples of green sand beaches include the Papakolea Beach on the Big Island in Hawaii, and the Kourou Beach in French Guiana.
Brown sand beaches
The Rockaway Beach in Pacifica in California is a a brown, chocolate-color beach. While the chocolate color might tempt you to take a bite of this peculiar-looking sand, I wouldn’t recommend it, unless you really love the taste of limestone and volcanic greenstone, because that’s what this sand is made of. The combination of particles from an impure limestone of bluish-gray color with those from dark greenish volcanic greenstone creates the chocolaty sand beach. I wouldn’t eat it, but I’d still like to see it!
Gray sand beaches
Gray sand beaches could have their origin in either a combination of shale with graywacke sandstone, or in the combination of basalt granules from lava rocks with fragmented shells, corals and other marine creatures. Gray sand beaches can be found in Shelter Cove in Humboldt County, California, various beaches on the Santorini Island, and beaches from other volcanic regions.
Black sand beaches
Just as some of the gray sand beaches are based on basalt, so are the black ones. The black sand beaches are made of basalt granules coming from the weathering of the basaltic rocks formed through the rapid cooling of the lava when it reaches the ocean water. Some famous black sand beaches include the Black Sand Beach in Vik, Iceland, the Pumalu’u Beach in Hawaii, the Muriwai Black Sand Beach in New Zealand, and Playa Negra in Puerto Viejo, Costa Rica. I’ve only seen the one in Iceland and it was a really impressive view. Impressive enough that I'm considering including also a black sand beach in one of my novels! And I definitely recommend visiting one, if you can.
Multicolored sand beaches
Natural multicolored beaches
A famous example of a multicolored sand beach is a beach in Queensland, Australia. It is called “Rainbow Beach” and for a good reason. It’s a beach where many different sand colors blend to create a one-of-a-kind landscape. While not all the colors of a rainbow are present, the combination of different hues of red, orange, and yellow do still provide a merging of colors similar to what we seen in a rainbow.
Where do these multicolored sands come from? They come from the nearby huge sand cliffs made from many layers of sand deposits over a long period of time. And the ingredient responsible for these sand colors is the iron oxide from the sand. The action of rain and wind on these enormous sand cliffs causes the sand of different colors to advance on the beach intermingle, giving rise to the rainbow sands.
Glass beaches
When I say man-made, I don’t mean intentionally made by people. But humans were, indirectly, the creators because these beaches are made of glass. They are present at trash dumping sites where glass was dumped over the years on the shore. That was before waste disposal and recycling systems were put into practice. In these areas, after decades of perfect conditions, like the action of the waves and currents, the pieces of broken glass were transformed into small, colorful pebble-like fragments that are now the basis of the glass beaches. Some examples of glass beaches include the Glass Beach in Kauai in Hawaii, and the Glass Beach near Fort Bragg, California.
I hope you enjoyed going on this virtual expedition with me around our world’s beaches. Let me know which is the most beautiful beach you've ever seen and what color was it? And if you’re curious to learn about the pink sand beach on the alien planet in my novel, you can subscribe to my newsletter, and I’ll let you know when my book is coming out.
*all images are from Canva
