The scene when they both fall to their death after Spike turns back to normal size makes it pretty clear that this is not simply a “puppy love”.
 
Changing yourself only because your loved one asked you can be a sign of inmaturity and inmature feelings.  
But changing yourself for another person without anyone asking you, that’s precisely what love is.

@SeraphimDawn  
Perhaps, but im certainly sure there will be a lot of mad people..

@And Brother I Hurt People  
It’s much less about the object itself and more what it represents. At bare minimum, the Fire Ruby represents his pony-like desire that manages to keep the “beast within” at bay.
 
It represents his willingness to give up part of what makes him what he is in order to satisfy who he wants to be with. That’s an incredibly important part of his character, that a creature who is supposed to be controlled by greed wants something bad enough to go against his nature to get it.
 
Then again I think that dragons don’t grow through greed exclusively, and that there are several ways. I personally like an almost “cutie mark” type experience, though it happens a little bit later and only after an incredibly emotional event. For most dragons this would probably winning their first fight or getting their first hoard. Don’t know what it would be for Spike.
 
He’s a little bit green about the concept of courtship, but his relationship with Rarity is a strange little thing that I can’t exactly see going away with age.

@QuelloScelto  
Show referencing of the comic… Would it be a good thing?

@Background Pony  
As long it doesn’t contradict the show it will be canon, if on the Daring Don’t episode turns out Twilight’s mom is Daring Do author then it will get stronger since the comics were the first to reference that.

@QuelloScelto
 
I don’t read the comics, so I wouldn’t know.
 
 
@Itsthinking
 
As much as I’m inclined to agree, the worth of the object might not mean much. I mean, your first love can be pretty intense; I’m sure that, in my younger years, if I could afford to give my first crush a gold necklace, I’d sure as hell get him one. Could be just that Rarity’s his first love and he’s not sure how to handle it.
 
That leads more into the “he’s too young to understand love” idea than the “physical appearance” idea, so you’re most likely right.

@Background Pony  
The writers of the show don’t and never have used the word “canon” to describe their work. It’s called “continuity.”
 
@And Brother I Hurt People  
@Zennistrad  
@QuelloScelto  
The mere existence of the Fire Ruby, a physical representation of passion, is enough to show that it’s more than just “puppy love” to him.

@QuelloScelto
 
*comic  
*canon
 
Sorry buddy, but comic can´t be canon

@And Brother I Hurt People  
I think the comics already proved that Spike’s loves more than her physical appeareance

@Background Pony  
Cut and paste like it was pasta on paper.  
The truest form of art.

Those are some nice copypasta hearts right there.

@Zennistrad
 
Nah, it honestly seems like a puppy love type thing to me.
 
I mean, it does suffer a bit from the fact that it seems like Spike is only in love with her physical appearance, but I’m sure if anyone dug enough into the show they could prove me wrong.

Another piece of Hasbro’s quality art.

Am I the only one who finds Spike’s crush on Rarity to be a little bit creepy?

How blatantly lewd.