Coprolites - fossilized dung is Bashny.Net

In these minerals "kakah" most of the organic matter replaced by inorganic minerals such as silicates and calcium carbonate. Coprolites are of great importance to science (for example, by the presence of the remains of fossilized bones in coprolites paleontologists can judge about the diet of extinct organisms), and are often used for unusual purposes.

In Germany and Britain coprolites used as fertilizers because of their high content of phosphoric acid. And if fecalith sand on the ground surface will be a beautiful drawing, so the British made from these souvenirs and various crafts. During World War coprolites were used as raw material for the production of phosphorous munitions.

via factroom.ru