Anatomy of the foot. The foot is one of the most complex parts of the body. It is made up of 26 bones connected by many joints, muscles, tendons, and ligaments. The foot is susceptible to many stresses. Foot problems can cause pain, inflammation, or injury. These problems can result in limited movement and mobility.
Bricks and tiles. Bricks and tiles are made from clay minerals. When wet, the clay can be shaped, and then fired to make floor, wall, and roof tiles, as well as house bricks. Think about the properties of clay: Easy to shape when wet. Strong and rigid when fired. Impermeable when fired. A thermal insulator.
The fact that household dust is made up mainly of dead skin cells is a myth. House dust is made up of mainly fabric fibers (from clothes, bed sheets, carpets...), bits of dry stuff like food or cardboard, untreated wood and good old fashioned dirt. There's also a lot of skin of course. This can vary considerably from house to house or room to room.