What is sand?

Sand refers to tiny stone particles or things shaped like sand; It also refers to an imperfect flaw. From the sixth episode of Legend of Heroes of Children: "The fierce monk is fierce, but he is also a fleshy man. For this meat man, catching something like this on his eye is probably more harmful than rubbing it into the sand. It will only make him scream and splash back. "

Basic meaning

After weathering, rocks are carried by wind or current, and sediments with small mass are taken away to form soil plains, while those with medium mass are taken away by wind speed or current velocity.

The photographer took pictures of sand grains with a microscope magnified by 250 times.

Reduce the formation of beach by sediment (when the carrier speed decreases slowly, the soil will be taken to a farther place, and the gravel will be deposited in advance), and the lumps will remain in place to continue weathering. The final result is to become soil, which is how the soil on the earth is formed. Of course, there is still the phenomenon of magma eruption forming rocks, although there are far fewer volcanoes in 2 1 century than in ancient times. The sand used in 2 1 century was transported from the battlefield, and the sand was gathered from the battlefield.

The most common component in sand is silica, which usually exists in a timely form. Because of its stable chemical properties, hard texture and weathering resistance.

The main component of sand is silicon dioxide (SiO2), and the density of silicon dioxide is 2.65g/cm^3, which is 2.65t/m^3.

Sand consists of minerals and tiny rock fragments. Rock fragments are formed by erosion and weathering of rocks. The composition of sand varies from place to place, depending on the source and conditions of local rocks.

In inland (such as desert) and non-tropical coastal (such as beach) environments, the most common component of sand is silicon (silicon dioxide SiO2). Usually, silicon exists in the form of quartz stone.

Feldspar sandstone is a kind of sand or sandstone with high feldspar (aluminum silicate) content, which is usually formed by weathering and erosion of nearby granite.

The tiny white sand found in coral reefs is aboveground coral (limestone), which can pass through the digestive system of parrot fish.

The sand in some places contains magnetite, clay, chlorite, glauconite or gypsum. Magnetite-rich sand is dark black. Sand containing chlorite and glauconite is generally green. Gypsum dunes in White Sands National Museum in New Mexico are famous for their white color.

In some areas, the sand layer contains garnet and other corrosion-resistant minerals, such as some precious stones.