Ajna is white in color, with two white petals. Inside the pericarp is the Shakti Hakini. It is depicted with a white moon, six faces, six arms, holding a book, a skull, a drum, a rosary, while making the gestures associated with granting boons and dispelling fears. The downward pointing triangle above her contains a moon-white lingum. In some systems the deity Ardhanarishvara, a hermaphrodite form of Shiva-Shakti, symbolising the primordial duality of subject and object, resides within the lingum. Above that triangle is another smaller triangle containing the bija mantra Aum.
Bija or Seed mantra
The seed syllable is Aum, or "Pranava Om", the supreme sound.
Ajna has two white petals, said to represent the psychic channels, Ida and Pingala, which meet the central Sushumna nadi (channel) before rising to the crown chakra, Sahasrara. The letters 'Ham' is written in white on the left petal represents Shiva. 'Ksham' written in white on the right petal represents Shakti. These two petals also represent the manifest and unmanifest mind, and are sometimes said to represent the pineal and pituitary glands.
Ajna translates as 'command' and is considered as the eye of intuition and intellect. When something is seen in the mind's eye, or in a dream, it is being 'seen' by Ajna. It is a bridge that links gurus with disciples, allowing mind communication to occur between two people. The sense organ and action organ associated with Ajna is the mind.
As Hindus believe that spiritual energy from the external environments enter their body through this gateway, they take great care to protect it with spiritually positive protecting forces. The various religious marks on the foreheads of men and women belonging to the Hindu faith (like holy ash, namam, vermilion etc.) are thus the blessed spiritual prasadam of their respective form of the Hindu gods.
Meditation upon Ajna supposedly grants the following siddhis or occult powers to quickly enter another body at will and to become omniscient. He realizes unity with Brahman; and he has the ability to create, preserve, and destroy the three worlds.
Directly above Ajna is a minor chakra known as Manas or mind. It possesses six petals, one for each of the five senses and one for sleep. These petals are normally white, but assume the color of the senses when activated by them, and they are black during sleep. This chakra's function is sending sense perceptions to the higher chakras.
Association with the body
Ajna is associated with the third eye on the forehead. It is sometimes associated with the pineal gland, which regulates the circadian rhythm and is actually related to a light sensitive 'third eye' (Parietal eye) found in some lizards, amphibians, and fish. it is also sometimes associated with the pituitary gland, the master gland of all endocrine glands, whose secretions control all the other endocrine glands.
In kundalini yoga, the practices said to stimulate the Ajna chakra include Trataka (steady gazing), Shambhavi Mudra (gazing at the space between the eyebrows), and some forms of Pranayama (breath exercises).
Comparisons with other systems
In Tibetan buddhism, this chakra is at the end of the central channel, which runs up the body to the top of the head, and then over and down to terminate at the forehead. The two side channels then continue onwards towards the two nostrils and end there. This center is frequently depicted in artwork as the 'third eye,' and is used in various meditations.
There is also a forehead centre above the third eye, which corresponds to the position of Manas (known as the Wind Wheel), one of the ten chakras in the Mahayoga tantra traditions.
In Qigong, the highest Dantian is located at this position. This is one of three 'furnaces' that converts the different sorts of energy in the body. In this Dantian, the spiritual shen energy is converted into wuji, the infinite space of void. 
According to the Kabbalah, there are two sephiroth located on the sixth level, associated with the left and right parts of the face. They are called Chokmah, wisdom, Binah, understanding, and it is at these points that the two side pillars of mercy and severity terminate, while the central pillar carries on rising to kether, the crown.
- In Tantra: Ajita-Patra, Ajna, Ajna-Pura, Ajna-Puri, Ajnamhuja, Ajnapankaja, Bhru-Madhya, Bhru-Madhya-Chakra, Bhru-Madhyaga-Padma, Bhru-Mandala, Bhru-Mula, Bhru-Saroruha, Dwidala, Dwidala-Kamala, Dwidalambuja, Dwipatra, Jnana-Padma, Netra-Padma, Netra-Patra, Shiva-Padma, and Triweni-Kamala
- In the Vedas, Upanishads: Ajna, Baindawa-Sthana, Bhru Chakra, Bhruyugamadhyabila, and Dwidala
- In the Puranas: Ajna, Dwidala, and Trirasna
- Swami Satyananda Saraswati. Kundalini Tantra
- Shyam Sundar Goswani. Layayoga – an advanced method of concentration
- 1 page 268, Kundalini Yoga for the West, Swami Sivananda Radha, Copyright 1978, Shambala Publications, Inc.
- "Third Eye Chakra". ASIS Massage. Retrieved 25 July 2013.
- Geshe Kelsang Gyatso. Tantric Grounds and Paths
- Andy James. The Spiritual Legacy of Shaolin Temple
- Dion Fortune. The Mystical Qabalah