Sand minerals are a stable fraction that is only altered very slowly. In spite of representing a quite inert and not very chemically active material, they are considered to be very interesting from the point of view of agricultural use. This is due to that fact that sand minerals, as they alter slowly, represent the future fertility of the soil. Therefore, determining the sand mineralogy is an effective measurement of natural reserves in the soil.

The following table lists sand minerals from the point of view of the possibilities of providing the soil with nutrients. The most interesting minerals will be those that have some specific nutrients in their structures and which have a high to average alteration velocity (for example, pyroxenes and amphiboles). On the other hand, we have quartz as a representative example of a very stable mineral, which also has a chemical composition that has no interest from a nutritive point of view.

Any planning of the use of soils in a specific region should go hand in hand with a mineralogical study of sands, as this would help us to determine which types of soils should be preserved (regardless of their current fertility) so that do not become exhausted in the near future.
For example, the following figure shows the mineralogy of two soils, with very different exploitation possibilities.

Bearing in mind both the fact that alteration is easy and the released elements (as shown in the previous table), it is possible to develop formulas to assess the future fertility of the soils on the basis of sand mineralogy.