These fossil raindrops are preserved in flagstones in the courtyard of the Stable Block at Nostell Priory near Wakefield.
It looks to me as if the flow of the river that laid down the sandy sediment was flowing diagonally, depositing platy minerals such as mica as the flow of the water slackened. Masons can easily split the stone into flat slabs by splitting it along these laminations.
This second slab was laid down on top of a rain-spattered slab, filling the indentations with sediment, a similar process to taking a plaster cast of a footprint. As in the previous photograph, the light is coming from the top of the picture, so these are dimples rising above the surface.
I’ve taken these photographs for my latest FutureLearn course, the Open University’s Earth in my Pocket: an Introduction to Geology. Our assignment this week is to look at building stones.