Guitar Harmony Five Frets Higher

Hi,

I've heard that a major thirds harmony is achieved by playing the same riff on the guitar four frets higher over the original riff.

I was wondering, does anyone know what the musical term would be for the same idea but played five frets higher, rather than four? I understand it would be a semitone higher, just wondering what kind of harmony it would be, if any? Providing it's not some sort of dissonance?

Thanks!