In article ,
lid says...

On Sun, 9 Mar 2014 22:57:01 +0000, Sacha wrote:

On 2014-03-08 17:21:43 +0000, Terry Pinnell said:

Can anyone identify these white marks on my drive paving please? I
reckon they've been visible for a few weeks.

https://dl.dropboxusercontent.com/u/...308-161824.JPG

Just a lichen of some sort. It gives new stone a pleasantly weathered
'antique' look, imo.

Some say this look can be achieved by washing brickwork with diluted cow muck.

I use a diluted mix of ground up lichen, diluted manure and yoghurt
to wash raw stonework. It doesn't immediately look like old lichened
stone but it's the quickest way to establish growth of lichens and
mosses that will make raw cut stone look venerable surprisingly
quickly... or hide the new repairs in old drystane walls.

Janet.