I have been walking over the tiles of exposed aggregate concrete in my garden for many years without noticing what treasures they are containing.

Only the current challenge made me see this little heart. (Its real size is not much bigger than 1/8 inch. At present, I am experimenting with macros. There is a detailled article about how to use lenses attached in reverse for macro photography at http://www.mplonsky.com/photo/article.htm ).