Why do Dragons eat gems? They have no nutrients. At least...
At least not for carbon-based life-forms.
What if they are based on silicon instead of carbon?
That way, it would make sense, because are gems based of silicon, as well.
So these gems wouldn't be like gems on earth, but rather like subterranous-growing vegetables, like potatoes, or, maybe more accurate, like truffles.

Remember this rock in "The Cutie Mark Chronicles"? The one which was split open by the Sonic Rainboom to reveal a filling of gems? Maybe that was some sort of fruit, like a pomegranate.

But this would mean there was a whole other tree of evolution in Equestria. This again means there would be more creatures who are silicon based. I think I have spotted two of them:

The cockatrice and the cragadile.
Both are, like dragons, reptiloid.

The cockatrice turns carbon-based life-forms into stone, maybe exchanging the carbon-atoms in the molecules with silicon, to make them edible. Like a spider spitting acid on victims to make them chewable.

The cragadile, on the other hand, seems to be part rock. More can't be said about it because there is not much information.

This also gives an explanation for rock-farms:

There, food for silicon-based life-forms is grown.

But apparently, Dragons can eat carbon-stuff, too.

Maybe the fire in their stomach has a purpose similar to the cockatrice's stare?

But there is an even greater problem for this: The Silicon-waste, other than the carbon-waste (Carbondioxide) is solid. That means dragons, cockatrices, and cragadiles would breath out a brick of useless matter every few seconds or minutes. Or is this, in the case of the dragons, also done by their fire?

Maybe that is why the fire can be used to teleport matter? Maybe it usually teleports the silicon-waste out of the dragons body.

And the cragadiles may accumulate their breath-outs in these rock-like things on their backs, shedding their skin from time to time?

What do you think about this?
And: Should I write a fanfiction on this?

3605444

Should I write a fanfiction on this?

Go for it. It makes sense to me.