Luna exalted.
anyways here some ideas.
The circle often represents the Sun, although a dot in the center is the usual.
The crescent the moon.
the 2 lines could be 11 or 2 1's, power number
The circle an half circle can be considered a sign existing before the elements or the cross. Mortal androgynous adam, the beginning...
the sign of mercury has those same elements except the 11s are crossed.