Yes, that's
f-f-f-fffflint 
And the bit about the falling trees I found that strange too. Perhaps it's to do with the way these rocks are formed (diagenesis?).
It is a lot easier to light a fire in the desert due to the dry conditions. Of course, it all depends on what you find or have at hand. One very useful tool for this purpose is a converging lens or glass (concave mirror, magnifying glass etc).
As for the omelette, you would if you had to!
In survival situations beggars can't be choosers!