The number 12 is present in a lot of phenomenas.
One year has 12 months in our solar counting, and a chinese year has 12 moons. 12 animals for their 12 signs in astrology and we have a cycle with coming back to our sign all 12 years. There are twelve ornaments on the Emperor's robes.
In the Buddhist tradition, we speak about of the "twelve nidanas » and "twelve deeds of the Buddha".
The 12 eyes Dzi bead is associated with authority, fearlessness, divine protection and providence.
So, it is an auspicious stone for one who want to undertake beyond his comfort zone, in unknown and/or difficult situation.