A Botany graduate, Nithya Venkat enjoys researching and writing about topics that interest her.
Sand is composed of loose pieces of rocks, minerals, and soil particles. Sand is found in beaches, lakes, rivers, the bottom of oceans, and desserts.
The constant weathering of landforms such as mountains and hills by natural forces such as rain, wind, and ice over millions of years has lead to the formation of sand.
Sand is granular in texture. An individual particle of sand is called a grain. Grains of sand can be rounded or angular in shape. They range from 1.6 mm to 2 mm in size. The color of the sand grains depends upon the geographical location and the environmental conditions of the surrounding place.
Formation of Sand
Sand formation starts when a landmass breaks down to form rocks. These rocks are further broken down into smaller and smaller pieces by nature's forces to form sand. Sand formation through natural forces can take anywhere from hundreds to millions of years.
The breaking down of rocks into smaller pieces by forces of nature is called weathering. Sand is the result of mechanical, chemical, and biological weathering that has occurred for over a million years.
Mechanical weathering is weathering that occurs due to the forces of the wind, water, and extreme temperature changes. Rainwater seeps into cracks and crevices of rocks turns into ice when the temperature falls below zero degrees centigrade.
When the surrounding temperature increases, the ice thaws. Over time, the freezing and thawing process causes the rocks to break apart into smaller pieces. These smaller pieces are broken into more tiny pieces to form grains of sand.
In deserts, there are extreme changes in temperatures. During the day, the temperatures are very high, and at night, it becomes freezing. The constant heating and cooling of rocks weaken them, and over time they break down into smaller fragments.
Mechanical weathering also occurs when the strong winds constantly hit against rocks and boulders, causing them to break apart.
Roots of trees growing in the sides of mountains penetrate deep and cause cracks in the rocks. These cracks become wider when the rainwater collects and freezes to form ice.
Chemical weathering weakens the rocks and aids in the process of disintegration through chemical reactions.
Water combines with carbon dioxide and forms carbonic acid; this carbonic acid dissolves the rocks causing them to weaken and break down. Temperature and moisture play an important role in chemical weathering.
Biological weathering is weathering that occurs due to the activity of plants and animals.
For example, lichens release chemicals that weaken the rocks. These weakened rocks can easily be broken down by forces of nature into smaller pieces.
Roots of trees that grow on the mountainside can cause cracks to develop in the rocks; this can be considered as biological weathering because it is caused by the growth of the plant roots.
The formation of sand results from all three types of weathering - mechanical, chemical, and biological weathering.
Composition of Sand
The composition of sand depends on the rocks present in the region and the environmental conditions. The color of sand depends on what the sand is made of and varies according to the composition.
Beach sand is made up of pebbles, shells, and small stones. Most of the beaches around the world are made of minerals like quartz and feldspar.
Quartz is made from silicon dioxide, and Feldspar is made of sodium, calcium, or potassium, along with quartz.
Quartz is found in abundance on beaches because they are hard and can survive in weather. Quartz can be broken down into smaller pieces, but they do not easily dissolve and disappear because they are strong and resistant to chemical reactions.
Other than calcium and feldspar, mica flakes can also be seen in beach sands.
The color of sand depends on what the sand is made of and varies according to the composition.
Presenting different colored sands around the world -
Black Sand Beaches
Black sand beaches are composed of volcanic minerals and lava fragments. These beaches are black in color because the volcanic minerals and rocks are in hues and shades of the color black.
The minerals that give the dark color to the sand are pyroxenes, amphiboles, and iron oxides. Black sands are heavier than the light brown colored sand and become very hot on a sunny day.
Many black sand beaches are found in Hawaii - Pololu Valley Beach and Kehena Beach, Honokalani Black Sand Beach.
Other Black Sand Beaches - Vik Beach in Iceland, Prince William Sound, Alaska.
The White Sands National Monument in New Mexico
The White Sands National Monument in New Mexico has about 275 square miles of white sand dunes made of gypsum that has been broken down over millions of years. The broken-down Gypsum gives white color to the sand.
According to the New Mexico New Port, a student journalism lab at the University of New Mexico, the white sands are the remnants of Lake Lucero that existed a million years ago.
Gypsum was produced at a faster rate than the water in the lake could dissolve, and due to this reason, layers of gypsum were left behind as the water evaporated.
The force of the wind broke down large pieces of Gypsum into Selenite (broken down pieces of Gypsum are known as Selenite).
The original Selenite formed had a clear surface, but over time, Selenite was eroded by the wind and developed many cracks. It is the reflection of light through these cracks that makes the sand look white.
Other white sand beaches worldwide – White Beach Boracay in the Philippines, The Maldives in the Indian Ocean, Wine Glass Bay in Tasmania, Grand Anse Beach in Seychelles.
Papakolea Green Sand Beach
Papakolea Green Sand Beach, also known as Puu Mahana Beach in Big Island, Hawaii, is surrounded by cliffs that are olive green in color. The sand on the beach is due to the constant erosion of a volcanic cinder cone called Diamond Head in Oahu, close to the beach.
The sand is composed of basaltic lava that is rich in a mineral called Olivine. Olivine is green in color and lends the shade of green to the sand.
Red Sand Beaches
Red sand beaches can be found in Hawaii, the USA, Rabida Island, Galapagos, and Santorini, Greece.
The sands in Rabida Island Galapagos are red due to the oxidation of iron-rich lava deposits and coral sediments that have been washed ashore.
The red color of the Red Sand Beach in Santorini is due to the erosion of the surrounding cliffs made of red color sedimentary rocks.
Kaihalulu Beach sand in Hawaii is blackish-red in color because of the erosion of the cinder cone called Ka’uiki Head on the Northern end of the cove.
Uses of Sand
Sand is an important component of building materials such as mortar, cement, asphalt, paving, plaster, and concrete. Sand is added to building materials to make them harder to bear more weight.
Pure quartz sand is used in pottery and glass-making industries to line the hearth of acid-steel furnaces because quartz sand can withstand high temperatures.
Sand is also used for the following -
- as a filter to purify water
- glued to paper to make sandpaper
- it is used as a sandblast to clean walls of buildings
Sand is formed by the erosion of land masses over millions of years. The composition of sand depends upon the place where it is found. Sand has many uses and plays a significant role in the construction industry.
© 2016 Nithya Venkat
Nithya Venkat (author) from Dubai on September 09, 2018:
It must have been an amazing experience to see the beaches first hand! Thank you for taking the time to read and comment.
Peggy Woods from Houston, Texas on September 09, 2018:
Great description of how sand is created and what uses are made from it. I have personally gotten to see white, pink and black sand but not yet any green or red. The black sand beach was in Hawaii. The pink sand was at the Coral Pink Sand Dunes State Park in Utah and the white sand was at the White Sand National Monument in New Mexico. I never even knew that there was a green sand beach. Thanks for the education.
Nithya Venkat (author) from Dubai on August 25, 2016:
AudreyHowitt thank you for your visit.
Audrey Howitt from California on August 23, 2016:
Still an excellent article!
Nithya Venkat (author) from Dubai on August 21, 2016:
It would be a fantastic experience to visit the White Sands Beach. You should visit Dubai someday soon!
Linda Bilyeu from Orlando, FL on August 21, 2016:
I had no idea there were so many different colors of sand. I have a friend in Tasmania who visits White Beach often, but never mentioned the sand was white! I am going to ask my friends in New Mexico to take me to the White Sands National Monument the next time I am visiting, unless it's too far out of the way. I would like to visit Dubai too, one day.
Nithya Venkat (author) from Dubai on June 22, 2016:
teaches12345 thank you and am glad you enjoyed this article.
Dianna Mendez on June 21, 2016:
I enjoyed this article. I would love to see the green sand beach, it is so pretty. We have the course sand on beaches around here with a few gypsum in between. So interesting to read these types of posts.
Nithya Venkat (author) from Dubai on June 15, 2016:
AudreyHowitt, yes all beautiful colors! Thank you for your visit.
Audrey Howitt from California on June 15, 2016:
So many colors! I didn't know!
Ann Carr from SW England on May 21, 2016:
It was great. The best bit is that I'm about to move to a town not far away but much closer to the sea! Can't wait.
Nithya Venkat (author) from Dubai on May 21, 2016:
annart it must have been great to grow up in a place with sea and beaches. I love the seaside too, thank you for your visit.
Ann Carr from SW England on May 21, 2016:
Lots of information here about something we all take for granted. There is a spot in the Isle of Wight, off the south coast of England, which has many different colours of sand with which I was fascinated as a child.
I love being near the sea and beaches; sand is a part of my childhood!
Nithya Venkat (author) from Dubai on February 20, 2016:
Surabhi Kaura thank you for your visit and yes we have to preserve nature and its glorious beauty.
Surabhi Kaura on February 19, 2016:
This is a very informative hub, Nithya. Nature is so beautiful. We as humans have a duty to preserve it, but alas! Loved the photos, my Sweet. They are truly gracious. Much Love.
Nithya Venkat (author) from Dubai on February 18, 2016:
Nell Rose thank you for the visit and share, much appreciated.
Nell Rose from England on February 17, 2016:
Hiya, just came back to share! wonderful hub!
Nithya Venkat (author) from Dubai on February 05, 2016:
rajan jolly thank you and yes the colors of the sand are mesmerizing.
Rajan Singh Jolly from From Mumbai, presently in Jalandhar, INDIA. on February 05, 2016:
Very informative and extremely interesting read. I'm mesmerized by the various colors of sand. Lovely photos as well and well written. Sharing this hub.
Nithya Venkat (author) from Dubai on February 03, 2016:
Jackie Lynnley thank for your visit and am glad you found this interesting.
Jackie Lynnley from the beautiful south on February 02, 2016:
So interesting Nithya! I guess it never entered this pea brain that sand came from rock and it is as logical as can be! I will certainly be comparing beaches to the rocks from now on! Thanks for the education! +
Nithya Venkat (author) from Dubai on January 29, 2016:
Nell Rose thank you for your visit and share. The green sand looks amazing!
Nell Rose from England on January 29, 2016:
Well I never knew that! Green sand! how amazing! And we also have red sand here in England! In a seaside resort called Paignton, I went there a few years ago. Amazing colors, fascinating hub! shared!
Nithya Venkat (author) from Dubai on January 27, 2016:
FlourishAnyway thank you, the colors are amazing.
FlourishAnyway from USA on January 26, 2016:
Fascinating stuff here! I enjoyed learning where all the different colors of sand can be found and why they are the colors they are.
Linda Crampton from British Columbia, Canada on January 23, 2016:
I love the photos and information about sand of unusual colour. I've seen black sand in real life, but I've never seen red, green or white sand. All of these colours look beautiful!
Nithya Venkat (author) from Dubai on January 23, 2016:
always exploring white sand looks great, thank you for your visit.
whounuwho thank you and yes sand is interesting to study in detail.
DDE thank you and yes they are so beautiful.
Devika Primić from Dubrovnik, Croatia on January 23, 2016:
Wow! The pebbles are beautiful. Interesting facts indeed!
whonunuwho from United States on January 22, 2016:
Interesting work my friend. Much more about sand than one realizes.Thanks for sharing. whonu
Ruby Jean Richert from Southern Illinois on January 22, 2016:
Interesting. I have never seen red or black sand. I love write sand.
Nithya Venkat (author) from Dubai on January 21, 2016:
billybuc thank you, that is true we never think about sand and wonder what it actually is.
Bill Holland from Olympia, WA on January 21, 2016:
I love articles like this one about stuff we always see but never really know much about. Great information here...thank you!