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Photographic gallery.  Thousands of particles under the microscope.

Spores, Sawdust, Etc. From Oil In A Load Tap Changer

Transmitted Off Crossed Polarized Light Illumination
Most of the objects in this field of view have only a carbon elemental signature except for
the paint particle in the middle left of the photograph. The paint particle can be identified
by the uniform size of the pigment particles distributed through the transparent vehicle (binder).
This is best seen at higher magnification. The particle will be seen to be a suspension of
minerals fillers, opacifiers, and pigments to produce the desired effect. This is a white paint
and titanium dioxide (rutile) is both the opacifier and pigment. The filler in this case is
probably fine clay or isotropic silica that is smaller than one micrometer and about the same
refractive index as the vehicle. Under those condition the filler is invisible unless the paint
is solvent extracted or ashed. The paint particle would have a titanium and a silicon signature.
The sawdust is the bright particle in the upper left and contains a row of five pores. The spore
is the brown particle just to the lower right of the center of the field of view. The very bright
smaller particles in the field are carbonate minerals, probably calcite (CaCO3). The clear
particles are polymers.