Piece of art

I have a carved stone as a piece of art in mu my home. I bought it in La Paz city from Bolivia, when I traveled for business one year ago. This piece of art is mysterious because have it has a drawing like of a tree leaf. It's actuallys a fossil. It's small and round. 

I keep it in a small box of wood. I Only take it out for to show my brothers. I don't use it for decoration, actually I use it as souvenirs of my travel to La Paz. Actually I don´t know how was it made. Maybe it's handmade, but like real.