What Is Sand?

It Makes Up Our Beaches, But What Is It?

What Is Sand?

When you’re at the beach have you ever stopped and wondered “What is sand?” You step on it, you play in it, you build with it, it gets in everything you have yet you wonder “What is this solid substance that can be found all over the world”?

Sand is defined as “a loose granular material that results from the disintegration of rocks that consists of particles smaller than gravel but coarser than silt, and is used in mortar, glass, abrasives, and foundry molds”. Sand is mostly made up of silicon dioxide in the form of quartz which is easily found all over the world. 

Due to weather (rain, freezing and thawing, heat and wind), these minerals and rocks get broken down into smaller and smaller grains. The more weathering, the smaller and finer the sand gets.  Also, the color of the sand is dependent on the minerals of the area.  Caribbean Islands produce more white-colored sand since the mineral and rocks combine with calcium carbonate (which comes from shells and reef-living organisms like corals and mollusks). The Hawaiian Islands produce more green and black sand due to having olivine (a mineral found in basaltic rocks) which makes up the ocean crust.  California has more purple-colored sand due to a concentration of garnet crystals (found in metamorphic rocks). These types of rocks can be found in subduction zones (areas with volcanic activity). 

Here on Tybee, and most of the eastern shores of the United States, our sand is mostly made up of silica (usually in the form of quartz crystals) and of shells from the area which creates a beige-colored sand. However, we have noticed there are different variations in the sand size and color depending on which Tybee beach you are on (North Beach, South Beach or Back River). Below

  • North Beach Sand: fewer waves equals smaller sand particles
  • South Beach Sand: more waves equals larger sand particles
  • Back River Sand: fewer waves equal smaller particles and appear more white since the concentration of shells and sea life is higher.
So the next time you are at the beach grab a handful of sand, look at it closer, and see what you discover.

Did You Know:

  • A piece of sand is referred to as a grain or particle, not a piece.
  • Sand comes in all shapes, sizes, and colors throughout the world depending on the natural rocks and minerals of the area. Colors can range from white, pink, orange, black, purple, green, and even brown.
  • Rougher ocean surf leaves bigger sand pieces and rocks on the beach since the smaller pieces are pulled out to sea since they are lighter.  Calmer seas bring in more fine sand and stone pieces since the waves are not strong enough to wash in the larger pieces.  
  • People who collect sand as a hobby are known as arenophiles. 
  • Sand can turn into glass with enough pressure and high heat. This doesn’t happen easily as the temperature needs to reach 3090 degrees Fahrenheit (1700 degrees Celsius).  If lightning hits sand it can become glass, but in very small pieces.
  • The Earth has (very, very roughly speaking) seven quintillion, five hundred quadrillion grains of sand (this is assuming a grain of sand has an average size and is calculated by number of grains in a teaspoon and multiplied by all the beaches/deserts in the world).
  • Building sand castles is an art form and there are competitions all over the world on who can build the best sand sculpture. Check out the images below from SCAD’s Sand Art Festival from earlier this year right here on the North Beach of Tybee.