East Beach ~ Barrier Beach

Physical Characteristics

What is sand?

Sand is really a mixture of very small pieces of rocks and minerals that are all different colors and sizes. Small pieces of rock are called sand if they are between 0.0625 mm and 2 mm in size. [That's pretty small- a millimeter (mm) is roughly the length of this -.] There is sand on Hawaiian beaches that is black and sand on the beaches of southern Florida is white. Here in New England our sand is beige colored.

Sand is formed when rocks weather or break down. Over time, wind, water, and changing temperatures (freezing/thawing) cause large pieces of rock to break down into smaller pieces. The small pieces are carried into the ocean from land by rivers and runoff.

How is sand classified?

If you classify sand by size, you look at the diameter of each sand particle. Very coarse sand, like you might see in a sand box, has the largest particles. The diagram below shows the actual size of sand particles from 0.5 to 2 mm in diameter.

• very fine   0.05 - 0.01mm
• fine   0.1 - 0.25mm
• medium   0.25 - 0.5 mm
• coarse   0.5 - 1 mm
• very coarse   1 - 2 mm