Description

"During the polishing and preparation of metallic samples for microscopy, sometimes cloth fibers get stuck in the fissures and microcracks. Here, fibers wrap around each other like snakes or tentacles, with a feature in the top left corner resembling a reptilian face.

The image was taken using scanning electron microscopy (SEM) in the standard secondary electron detection mode. The particularly bright spots (that look like a reflection of sunlight) are due to "charging" of the sample: Because the fibers are non-conductive, electrons will build up on the surface, which appears very bright in the detector. The sample was sputter-coated with gold to alleviate charging, but some regions, such as inside of cracks like here, aren't as well covered by the thin layer of gold."