The sixth chakra is the brow chakra, also called the chakra of the third eye. The color assigned to this chakra is indigo, or purple. This is the chakra of intuition, of thought and of spirituality.
If you have a healthy sixth chakra, you are at peace with yourself, and are able to study and investigate issues of spirituality. You will also be able to develop your psychic awareness.
If, on the other hand, your sixth chakra is unhealthy or closed, it could cause you to jump from idea to idea with little focus. It could also cause you to cling to a single idea without any ability to even consider or discuss any other idea- hence 'close minded'.
If your aim is to open and clear your sixth chakra, try working with amethyst or lapis lazuli. Focus on the spot just above and between your two physical eyes. You may get a glimpse of your third eye, usually very beautiful, looking right back at you. Even if you don't see it you may become aware of it. You may imagine a deep blue flower gently opening its petals wide.
If the issue is that you that you are overwhelmed with psychic information and it is interfering in your everyday life you may ask the chakra to gently close. Either visualise the third eyelid closing or petals of a blue flower folding softly inwards.
Anodea Judith's DVD is a beautiful introduction to the chakras.
The Seven Chakras