If the parent material is a red lava rock, the soil could also have a red color. Grey soils are indicators of permanent water saturation and no drainage. These soils are commonly clays and fine silts, which are often stained by minerals and objects that wash down. This type of soil also holds large amounts of iron in the ferrous form. Soil texture is created from both the parent material and the climate under which it forms.
Texture is determined by the size and amount of particles of which it is composed.
The main three classifications of texture are sand, silt and clay. Figure 1 Structure of soils comes from the aggregate composition. Aggregates are clusters of particles of a variety of shapes and sizes. They can form crumb like, granular, plate like, blocky or many other shapes. It is the aggregate composition that will determine whether the soil will be a good plant soil, leach its nutrients easily, or be virtually dry and sterile of organisms.