The next day, they realized that the sand and natron under the fire had melted then cooled into glass.

VOA: special.2009.09.16

But you must be careful. It is easy to get lost in the waves of moving sand especially during sandstorms.

VOA: special.2010.01.04

Obsidian is a kind of black glass formed when the heat of a volcano melts the silica material in sand.

VOA: special.2009.09.16

For example, lightning can create tubes of glass when it strikes sand that has the right combination of minerals.

VOA: special.2009.09.16

Instead,you should use sand from rivers or from other areas of land that are not near the sea.

VOA: special.2009.09.14

For example, you can add sand to prevent tiny breaks or lines from forming in the finished product.

VOA: special.2009.09.14

Water in the sand between the two pots evaporates through the surface of the larger pot, where drier outside air is moving.

VOA: special.2009.02.09

Hundreds of the islands are only pieces of sand that extend a few feet out of the water.

VOA: special.2010.03.22

They form when plants hold sand in the outer parts of the dune but the center of the dune continues to move.

VOA: special.2010.01.04

They knew that the black line was formed by trees, and the white line was the sand.

VOA: special.2010.03.06

The soaptree yucca plant can make its stem grow longer to keep its leaves above the sand.

VOA: special.2010.01.04

This sea wall is built right into the hills of sand that make up the coast.

VOA: special.2009.06.01

It lies between sand hills covered with pine trees and rich farmland near the Mississippi River.

VOA: special.2010.01.03

The soil should be full of loam, a mixture of sand, silt,clay and organic material.

VOA: special.2009.04.07

Portland cement is a material that holds together the sand and crushed stone in concrete.

VOA: special.2009.12.01

The sand in the two arms moves faster than the sand in the center.

VOA: special.2010.01.04

The desert sand around the well had melted into glass from the extreme heat.

VOA: special.2009.03.22

The bright white sand dunes are always changing,always moving, like waves on the ocean.

VOA: special.2010.01.04

The long,brownish red wall protects the white sand and coastal grasses from the sea.

VOA: special.2009.06.01

Driven by strong winds, the sand moves and covers everything in its path.

VOA: special.2010.01.04

Yet,a few plants have developed techniques to avoid being buried by moving sand.

VOA: special.2010.01.04