Photo 073

This photo was made without a support in the very inconvenient place. It was a big surprise, that the image sharpness was very acceptable. This is a roofing slate. The surface area is approximately 4x5 cm. The small yellowish specks are apparently a plant origin (it can be some fungus).

But here is round spot with the bright middle... Possibly, it was also plant origin, but birds was flying here... Solve themselves...