sharing our knowledge.
Photographic gallery.  Thousands of particles under the microscope.
Rubber Wear Particles Paint Sphere Under the Microscope Pencil Lead Dust Under the Microscope Magnetite Sphere Hematite Wear Metal Iron Mill Scale Under the Microscope Nigrospora Spore Insect Hair Toner and Paper

Though some of these particles are from combustion (cenospheres), they are not from an uncontrolled fire.

Black Particle in an Office Black Particle in an Office