The crown chakra represents the channels, the gateway to truth, divine connection, strength and humility.
Location: In the center of the crown
Organ: the brain, the pineal gland
Color: White / Purple / Gold
When chakra is balanced: Seat of the soul, connection with the Higher Self, unity, transcendence, relationship with the unknown
Shadow: Grief, feeling you are separate from existence, fear of death
Yoga exercises to strengthen the chakra:
Ego Eradicator 
Maha Bandha 
Sat Kriya