Snowflake Obsidian is said to purify & ground body, soul & aura. It can centres & focuses attention, which can be really useful in chaotic or stressful environments. The black of the obsidian & the white of the snowflakes represent the balancing of dark & light, yin & yang & this stone is known to be a bringer of balance between two opposing sides.
 
There are many dualities that the stone symbolises. It helps you see the bright side & reminds you that even though you will encounter tough times, there will always be light inside yourself.
In meditation, it facilitates looking inward & finding the inner strength to overcome whatever obstacle is in your path. It is protective of both your space & your energy, so it is useful for keeping your space calm & balanced, and also for shielding you from any negative energy.