The bowed 12-string guitar has a specific tuning that produces long-lasting low resonances and a sparkling timbre. You can see the tuning in both hertz and ratio (in octaves on the 12 string)
In my work, Lyrawae, I derived the following scale from the combination of the pythagorean harmonics, equal-tempered frets, and the open tuning (below). It is an overtone tuning and so it has different pitches at different octaves. The slightly uneven octaves and unisons that result from this beat slowly and add an interesting timbre within the even tones.