A moon is a unit of time corresponding to a month.
9 moons were chosen as a standard for the gestation of almost every child before entering a world which they can choose to destroy or cherish. Teach wisely.
Why not choose a recent memorable moment/event within the last 12 months that made a positive impact on your life as this necklace can then be made up with the same number of cracked beads, for you as a reminder of that special moment.
Avoid dropping or knocking the beads against hard surfaces as they are delicate.