There are many different types of sand around the world. It
is a very curious material composed of many mineral particles and
divided rock. The most common material that constitutes the sand is the
silicon dioxide. The size of a sand particle normally ranges from .0625
mm to 2 mm; if the size of the particle exceeds the range it is called
gravel; however, if is smaller than .0625 mm is generally called silt.
Now even when most of the sand is generally made of silica (silicon
dioxide) not all of it is composed in the exact same way.
The types of sand vary according to its location. The beaches around the world are great places to find sand. Not all of them have the same type though; they come in a variety of colors and textures.
In some regions there are beaches of white, black, green and even red sand. All of the types have different origins and depend entirely on their geological conditions. Some of the sand kinds occur more often than others for example: the white are more common than red and green ones.
Types of Beach Sand Categories:
1- White Sand Beaches
One of the most popular types
of sand can be found in tropical touristic destinations like Punta Cana
in the Dominican Republic. The white sand in most beaches consists of
quartz. Quartz is similar to silica in chemical composition but the
structure can be quite different. It is known to be the main component of
sand and can be found in many beaches. A beach with plenty of quartz
looks very white and shiny.
Other components of white beaches are little fragments of corals and broken seashells. In beaches where the waves are very strong the edges of seashells are normally broken by the action of the waves creating a smooth surface.
You can also find other beaches where waves are very weak creating coarser sand grains and a less smooth surface.
2- Black Sand Beaches
The black type is a bit unusual. The components of the black sand can be different from those of the white one. It is normally found in 2 forms. One type consists of small pieces of lava and the other as a combination of minerals created by sedimentation. In the island of Maui (Hawaii), for example, there is a beach with plenty of black sand.
This specific black sand consists of basalt which is a
material produced by volcanic eruptions. The basalt grains get their
shape by the impact of the winds and waves. Other minerals that can
create black sand are magnetite and hornblende. These minerals are
often transported to the beach by the rivers.
3- Greensand Beaches
Greensand can be found in certain beaches around the world. That kind of sand is due to the presence of a certain mineral called glauconite. The grains formed from glauconite have a dark green appearance and are quite rare. France is one of the few places where greensand beaches can be found. Not all green sand is composed of the same mineral. Other minerals that might give the beaches a green color are: malachite, serpentine and olivine.
4- Olivine Beaches
Among the different types of sand; the olivine grain is known to be extremely rare. One of the particularities of this sand is the green color and its unstable nature. The mineral is formed from a special group of rocks that breakdown fairly fast under normal environmental conditions. They tend to be more common in regions with volcanic activity. The crystals are created from basalt lava remains in the surrounding area. The higher density of the olivine compared to other grains allows it for a significant amassing of the rock on the beach area. Popular beaches with olivine sand can be found in southern party of Hawaii and Guam.
5- Red Sand Beaches
Some types of sand have a slightly reddish appearance. Sometimes this is due to the mineral known as garnet. The majority of the sand grains contain a low concentration of garnet but under certain conditions some rocks can be formed with a high concentration of it. Sand that contains a high amount of garnet can be easily identified by the red color that intensifies in direct proportion to the mineral. Australia and India are well known for having beaches with a high garnet content.
The red color may also be caused by iron. There are hills in Maui where the amount of iron is so high that sand nearby has a red tone. Beaches like that are quite rare so if you find one enjoy it the most that you can.
6- Biogenic Sand
This is one of the most curious types of sand. The biogenic sand is basically made from the marine life; by looking at it really close you can see all kinds of grains with different sizes and shapes. Many organisms living in the sea have exoskeletons formed from calcium, silica and other materials. Clams, coral and snails are typical examples of sea creatures that can form biogenic sand. Not all the sand has the same composition; depending on where the beach is located the remnants of the organisms may vary. Also some of it may be a mixture of other minerals with organism fragments.