What Is Dust Made of?
Dust is made up of many things. House dust has outdoor dust, plus a lot of other things. The exact contents in it probably vary from house to house. House dust typically contains bits of dry skin, which are always falling off people and pets.
Dust usually also has tiny fibers of human hair, pet hair, and lint from rugs and clothing. In the dust you could collect from a windowsill, you would find soot, ash and cinders. These particles are the result of the burning of fuel in homes and industry.
Outdoors, dust contains just about anything that can be broken down into small bits and moved around by air currents. You may find tiny shreds of animal and plant matter in it, such as spores, pollen grains from flowers, yeasts, bacteria, and bits of wool, cotton and hair.
The greatest part of it consists of powdery soil that is constantly being blown about. It may drift for hundreds of miles before it finally settles due to gravity. Rain also brings dust down with it.
And some of it is from space. Little rocks are always falling to Earth. Some of them have been around since before the age of dinosaurs, and they are still being blown around the world, settling on our dressers.