There are four main soil types, each created by a different process, and each made of different materials. While one kind of soil may be good for making and building things, another may not. While food and plants can easily grow in one type of soil, those same plants would have a tough time surviving in other types.
Sand is the number main particle found in soil. You can tell it's sandy soil by how rough it feels as you rub it between your fingers. This soil is a combination of rock, quartz or silica. Sandy soil is what's needed in areas requiring drainage, like baseball fields, but doesn't contain enough nutrients to grow strong, healthy plants. When melted down, sandy soil becomes glass.
Another type of soil is clay. When it's dry, clay feels smooth to the touch, but it becomes very sticky when wet. It's made of small, inorganic particles been worn down from rock. Clay can be full of healthy nutrients, but doesn't allow enough water and air to pass through to support most plants. Because it's so sticky and dries hard, clay is very good for building and making pottery.
Silt is a combination of sandy soil and clay. You can tell silt by how powdery it feels when it's dry. Unlike clay, silt does not become sticky when it's wet.
Loam is a combination of sandy soil, clay and silt. It breaks up easily, allows for organic activity, stays moist while allowing for drainage and air circulation. Loam is the best soil for growing plants. In fact, gardeners often mix loam in with other soils like sand and clay.