The high concentration of mineral filler is evident along the edge of this particle. Without reflected darkfield
illumination the color of the particle can't be determined.
Transmitted Off-Crossed Circular Polarized Light
Shoe wear particles as presented here refer to shoes with an elastomer sole. These may be a variety of colors but tend to have a very high
mineral filler content, typically calcite. They may also have a high plasticizer content. Some are acetone soluble.
Significance in the Environment:
shoe wear particles are common in high occupancy indoor spaces.
Shoe wear particles have a much higher mineral filler content than tire or belt-drive wear particles. The mineral filler particles also tend
to be much larger than that in tire or belt-drive wear particles.
The elastomers used in the soles of many common shoes are relatively soft and have a high coefficient of friction the
result is that they create small tapered cylinders of wear, just like tires or any other elastomer used for the sake
of its high coefficient of friction. Shoe wear typically has a high mineral filler components as can be seen here.