Public domain photos

The image shows a close up of a rock with a small amount of dirt on it, and at the bottom of the image there is some text and a scale. The rock appears to be made of limestone, and the dirt is visible on its surface.

The image shows a close up of a rock with a small amount of dirt on it, and at the bottom of the image there is some text and a scale. The rock appears to be made of limestone, and the dirt is visible on its surface.Open in library