Clay blocks are not affected by gravity.
Finding and Gathering Edit
Clay is common and found in deposits on the surface alongside dirt in biomes with green, as is not patchy, grass (rainfall value of 500 or more). It's appearance is that of a dirt block with gray stripes blended in. Grass grows on clay deposits
hiding them and causing them to blend in with the dirt around them.
To find clay look for and dig below goldenrod flowers, which grow exclusively on clay. Clay can also occasionally be spotted on the edge of cliffs or by bodies of water as grass will not grow on the sides of the blocks. Clay also cannot be plowed with a hoe, unlike dirt.
Clay is collected with a shovel dropping 1-3 balls of clay that cannot be placed.