Is the desert sand closer in composition and in the degree of rounding and sorting as the river sand or the beach sand and why

The three sand are similar in composition, since all are formed 90% by quartz. They are also similar in roundness, as they all have large particles that allow a very sandy soil with low water retention.

Explanation:

The desert area of the river and the beach have a very similar composition, since 90% of these sands are composed of quartz. however, the similarity does not mean that these sands are the same, as they are not, since the sands of the beach and the river may have a little more material, such as animal remains, making these sands also have carbon in composition, something that desert sand has in less quantity.

In addition, both sands have large particles that promote strong aeration in the soil, but a very rapid loss of organic matter.