Are Crystal ponies actually not a race?

[Zoraxe 546]

@@TailsIsNotAlone,

 

Maybe, but then again the Crystal ponies do look different before Sombra was defeated. So its hard to say.

[SCS 7,537]

I think the crystal ponies are their own race. Anyone can radiate love and harmony from themselves if they attain a necessary level of spiritual evolution, as indicated by the mane six sending out the rainbow light from their castle at the end of season 4. However, the crystal ponies in particular seem predisposed to this ability, and they use the crystal heart to achieve the same goal of spreading love, light, peace and harmony. It is very possible that they and everyone else in Equestria exists for a reason, and while each of them have their own individual free will, meanings and purposes, collectively they play the role of helping to grow and maintain harmony in Equestria. The mane six's experience with them, among their many other lessons, resulted in them being able to do the same. 

 

However, the crystal ponies are not perfect or invincible. It seems that it is possible to wrest control over them if a sufficiently strong negative force succeeds in breaking up their unity. However, as long as they remain united, which must be chosen through free will and determination, they are invincible. Similar to the elements of harmony, nothing can defeat the crystal heart as it's simply against the deepest harmonies of order, nature, and life itself.