Fossilized tree

These steps are a feature of my garden. They are not ordinary stone steps, but are made of a fossilized tree which I found 15 years ago in the neighbourhood. I did not know what it was then, but I liked the unusual texture of the stone and hauled them to my garden with the help of some village boys. We could not move the big pieces as they were too heavy. Those huge pieces were destroyed by the construction workers later, when the roads were being laid in this suburb.
It was only much later that a geologist friend who came to my house recognized the pieces of stone as parts of a petrified tree.