What is characterized by soil that passes the 3" sieve but does not pass the No. 4 sieve?

Soil that passes a 3-inch sieve but does not pass a No. 4 sieve is classified as gravel. This classification is based on the particle size distribution defined in soil mechanics. In this context, the 3-inch sieve allows larger particles to pass through, while the No. 4 sieve retains smaller particles. Gravel is characterized by its relatively larger particle size, typically ranging from 4.75 mm to 76.2 mm (or about 0.1875 inches to 3 inches). Thus, when soil can pass the larger sieve but is retained by the smaller sieve, it indicates a predominance of larger gravel-sized particles in the soil sample.

In contrast, sand, clay, and silt represent different sizes and types of soil particles, with sand being finer than gravel, clay being much finer and cohesive, and silt being somewhat finer than sand but coarser than clay. Each of these materials would have distinct sieving characteristics that do not align with the criteria given in the question, further confirming that the correct classification is gravel.