Can't uv map texture the bottom of an object.

Hello blender artists!
Today I have tried to make a simple crystal, but I had a problem with the textures.
I want both sides of the flat (not entirely) crystal to be textured, but for some reasons ,blender just won 't do that.
For some reason I can 't upload of what I have done either, so I will try to discribe it:
1.I made it out of a cube, with 1x subdivision modiefer.
2.Than I scaled it a bit to make it look like the crystal I wanted.
3.Than I marked the middle line as seamed.
4.Than(lol, dunno what to say instead of “than” in this situation…) I unwrapped it.
5.Thanks to the seam, I had 2 nice forms( both side of the flat crystal), so I loaded in the texture I had made.(the bottom and top of a crystal, so 2 pictures in one, for the 2 uv map forms).
6.Voila: I went from solid to texture, and the top was textured, but the bottom wasn’t (it was black…)

Anyone who knows how to fix this?

For some reason I can 't upload
Try harder. Upload to