Location - In the middle of the forehead between the eyes. 
Sanskrit Name - Ajna. In Sanskrit this means to perceive.
Related Color - Indigo
Musical Frequency - A
Ruling Planet - Sun
Supporting Crystals - Amethyst, sodalite, kyanite
Essential Oils - Geranium, lavender, juniper
Physically Governs - The eyes, sinuses, forehead, hypothalamus, brain, and the pituitary and pineal glands.  
Physical Dysfunction - Visual and sinus problems, headaches, hormone function.
Emotional Dysfunction - Nightmares, learning difficulties, hallucinations.
When Balanced - Charismatic, highly intuitive, non-materialistic, may experience psychic experiences.
Signs of Imbalance - Highly logical, dogmatic, authoritarian, arrogant.
When Blocked - ​Undisciplined, fears success, schizophrenia, sets low goals.