Sahasrara or Crown is the 7th and the highest one of the main 7 chakras. When all 6 lower major chakra centers have studied, you can move to Crown, which is about wisdom and spirituality. While study Crown, you become more aware for world around you, and you create connection with universal wholeness.
Sahasraras "lotus" have 1000 petals and it is located at the top of the head. It is connected to 12th chakra center about 30 centimeters above it. 12th center is I AM point, where we understand that we are that whole development process of universe, and not our ego-minds. When we watch some object around us, we understand that we are that object as well as our physical bodys, not more or less. Everything have made by pure light (solidness of matter is illusion) and we are that light or pure consciouss energy itself, and we start manifest that God-being to our physical bodys (but not perfectly). Our bodies become more our original being, pure light, and we manifest siddhi powers. Anything that is destiny of all. All that is possible, when awaken from that day dream, where so many people life. Its usually call enlightenment.
Colour: Violet, fuxia, magenta
Mantra: NG, AUM
Jesus of Nazareth, Siddhartha Gautama, Sathya Sai Baba, Ramana Maharshi. Couple of enlightened persons. Enlightening is to be HERE and NOW, in this eternal moment, with divine bliss, love, joy and happiness. When one have control over his/her ego. You cant stay consciously awaken in THAT moment, if you try to feel pleasure and avoid unconfortable situations. Its your ego that wants to feel pleasure always (from sex, food, etc.). Happiness is original state of mind and if we completely ignore wants of ego, we stay in pure joy and bliss. It is feeling inside your head, and outside things dont effect to it. What i mean by that? No matter, are you sitting in peaceful forest or example in prison, you feel inner peace anyway. You feel it always.
With blocked Sahasrara chakra person is not very spiritual and maybe addicted to feeling pleasure. Headaches can be common. Life looks like only living without intresting purpose. When its opened, person is open to spirituality and connected to universe. If over-active (energy is focused to that center), one cant live ordinary life and it is hard to success all simple things like job, example. Person can maybe ignore his bodily needs.
To focusing energy to that chakra, visualize violet sun on top of head, while meditate. Other things that can open this chakra are meditation, visualization, fantasizing, praying, reading about spirituality, thinking life itself. All intellectual and spiritual activities can open that chakra.
Colour of Sahasrara is violet so focusing to color violet send more energy to that chakra. Use violet clothes, watch violet etc. Thats also knew in colour-therapy.
Read my articles about lower chakras. You find them there: http://www.mytelekinesis.com/angyana--third-eye-aeromaster.html