I wanted to repost doublescream's question since I could not find the answer.
I have hatched my first dragon and, of course, now patiently await enough dragon scales to continue on down the Glimmergate Quest line. I am considering purchasing a Mithril Dragon egg with gems which I'm hoping will fill two needs, scales and mithril. However, I wanted to know if I keep sending my knights to Traverse the Desert Sands, will they pick up another burning ember even if I haven't purchased the egg yet?