Fossil

 
When I lived in the UK, there was a large corn field where I walked daily with the dogs and the children.  Every walk uncovered fossils on the ground that we'd pick up and bring home.  They were mostly extinct ammonite species from the Triassic/Jurassic period and most were left behind when I moved back to Canada.

The simple shape is appealing and the colours that come from age and earth add to the appeal.  Using granulating watercolours in Lunar Black and Lunar Blue (a combination of Lunar Black and Pthalo Blue), they are perfect additions for creating texture and age.
Source : illustratedlife[dot]blogspot[dot]com