Earth and Fire Skulls

So over the last couple days I have done a few new skulls for an upcoming project.  The first is an ink drawing I started in my sketchbook a few months ago but just decided to complete this week.  The other one was something I thought of once completing the Earth Skull.  It started as more of a test, seeing what I could do tweaking the the sun picture I did a few days ago.  I liked the way the test started to go so I kept going and basically redrew the whole thing and now there is the Fire Skull.