Hmm... The stark contrast between the light and the shadowed side does imply metallic or perhaps crystalline quality, but here it feels overly strong compared to the outline's intensity/thickness/just overall prominence. Perhaps greater texturing work could've helped to give the crystalline look without making it feel overexposed.
That said, I do like the linework and the general feel. The ruby necklace looks sweet, the magic field is quite intense, the hair is done well (and there, the gradient works much better, as her hair colour does shift like that), and the eyes and the face (with the ear and the general pose being a necessary pair of components, as well) give a beautiful portrayal of emotion. Well done!
Now, I would be hard-pressed to refuse this Rarity whatever it is she might be possibly wishing or asking for. Of course, certain limitations apply, but the point is still there.