Jagged Outback Rocks

From Draw Like Da Vinci: Leonardo da Vinci made many studies of mountains for his paintings and also included them in his landscape drawings. His paintings have mountains in the background and/or rock formations in the foreground. For example, mountains appear in The Annunciation and Mona Lisa. The Virgin of the Rocks has both rocky caverns and distant mountains. 

When drawing rocks, define their ridges with sharp lines. Use stark contrasts between alternating light and shade all the way to their bases.