Black Particles Under the Microscope

Black Particles

This is part of a guide to the identification of particles seen in samples of free particles. This file includes particles that appear black with transmitted light that may have any shape or reflectivity, both homogeneous and heterogeneous.

Black Round Particles, Transmitted Light

These are round particles or round agglomerates that appear generally opaque or very dark with transmitted brightfield illumination.

Round Opaque or Dark Particles Bright At Least In Part Between Crossed Polarizing Filters

Transmitted Brightfield, Paint Spheres

Transmitted Polarized Light

Transmitted Brightfield, Hematite

Transmitted Polarized Light

Round Opaque or Dark Particles Bright Only At The Edge Between Crossed Polarizing Filters

Magnetite Sphere (See Below for reflected light)

Round Opaque or Dark Particles Dark Between Crossed Polarizing Filters Even At The Edge

Toner Particles

Cenospheres

Black Round Particles, Reflected Light

These are round particles or round agglomerates that appear generally black or very dark with reflected darkfield illumination.

Particles that reflect the image of the illumination source.

Magnetite Sphere

Particles that show complex highlights with reflected darkfield illumination. This is normally due to complex surface textures.

Cenospheres

Particles that show no highlights with reflected darkfield illumination. This is normally due to a transparent matrix containing small, highly light absorbing particles.