Three Types of Gravel

Pea Gravel

• Pea gravel is a popular, inexpensive naturally harvested variety composed of small round pebbles that are comfortable to walk on. These traditionally come in an off-white color and can be used for a variety of purposes in the home, from composing a driveway to filling the bottom of a fish tank. Pea gravel also comes in various colors, both natural and unnatural. These are used for decorative purposes.

Lava Rock

• Lava rock is an extremely lightweight pebble-sized type of gravel. It has a natural red color and sharp edges. Some use it for decorative purposes, because of its color, but it has other possible uses as well, such as to grow plants in. Being a porous type of gravel, lava rock is able to retain more water than other types. This led to its use in growing orchids and other plants in a hydroponic manner. One downside to using lava rock is that its sharp edges can harm plant roots.

Crushed Stone Gravel

• Crushed stone gravel is a term used to refer to crushed limestone or dolemite that has been filtered into various sizes, ranging from ¼-inch to 3/8-inch pieces. This gravel has sharp edges and is used less for decoration than for more practical applications. It is often used to produce concrete and can be mixed with tar for use in roads and driveways. It can also be used on its own for driveways.

Gravel Production

• The three types of gravel mentioned above, and most gravel in general, are composed of naturally occurring rock, though the processes that turn these rocks into gravel vary. When dealing with limestone, granite or dolemite gravel, man-made mining operations grind up the rock into gravel using machines. Other types, like pea gravel and lava rock, are created by natural process. Rocks break down due to weathering and many are shaped by running water in streams before being collected and sold as gravel.