I really like the alignment of the two mountains. Is that Fuji in the background? I might have tried to make the sand mountain look more like its bigger sibling, but the alignment is great, the colors are great, and the scale is great. That sand mountain looks a bit like a gnome from behind, by the way. Perfect!
Oh, I am split here. Your concept together with your composition are strong, but your execution is a tad on the course side. The rendition of texture is course, and there are some very obvious halos around the horizon. On balance, the one cancels the other, so 5.