Amethyst is one of the best:

"Amethyst activates and balances your Crown Chakra.

Amethyst is the premier spiritual stone, providing purifying, healing, and protective energies to help clear, open, and balance the Crown Chakra. Amethyst connects the physical plane with the higher realms, pulling the high frequency vibrations into the Crown Chakra, through the Third-Eye, for processing by the rest of the chakras. Many work with Amethyst for it's protective bubble of light that is activated when one holds or wears this stone. Working with Amethyst to clear the Crown Chakra can create a sense of completeness and belonging, setting the stage for future development.

Located at the very top and center of the head, the Crown Chakra is known as the seat of higher consciousness and cosmic awareness, and is our connection to our own divinity. It is usually wide-open at birth, closing up during early childhood, to be developed during adulthood. The Crown Chakra is connected to the Ketheric layer of the aura (spiritual body), and sends energy to the pituitary gland to be distributed to the brain and nervous system. The Crown Chakra usually becomes blocked from negative experiences with organized religion, and this blockages severly stunts one's spiritual growth. Activating and balancing your Crown Chakra can help you to discover your greater purpose in this lifetime.

Amethyst's highly spiritual energies can be used with the Crown Chakra, during meditation, to gain a deeper understanding of the universe, and one's place within it. Meditating with Amethyst on the Crown Chakra can bring higher awareness and a connection to the Divine. Physically, Amethyst can help to balance out brain and nerve disorders, and to correct disorders of coordination. Amethyst's calming energies can also be felt through the Crown Chakra, bringing a sense of peace, and a knowledge of the Divine Perfection of the Universe, which can contribute to significant spiritual development."

And from the Crystal Bible:

Crystal Bible)

COLOR: Purple to Lavender

APPEARANCE: ransparent, pointed crystals. May be geode, cluster or single point. All sizes

RARITY: One of the most common crystals.

SOURCE: United States, Britain, Canada, Brazil, Mexico, Russia, Sri Lanka, Uragray, East Africa, Siberia, India

ATTRIBUTES: Amethyst is an extremely powerful and protective stone with a high spiritual vibration. It guards against psychic attack, transmuting the energy into love. A natural tranquilizer, Amethyst blocks geopathic stress and negative environment energies. Its serenity enhances higher states of consciousness and meditation. Amethyst has strong healing and cleansing powers, and enhances spiritual awareness. Traditionally, it was worn to prevent drunkenness and has a sobering effect on overindulgence and physical passions, supporting sobriety. It overcomes addictions and blockages of all kinds.Used at a higher level, Amethyst opens to another reality.

Amethyst is extremely beneficial to the mind, calming or stimulating as appropriate. When you meditate, it turns thoughts away from the mundane into tranquility and deeper understanding. Mentally, it helps you feel less scattered, more focused and in control of yuor faculties. It enhances the assimilation of new ideas and connects cause with effect.

This stone facilitates the decision-making procress, bringing in common sense and spiritual insights, and putting decisions and insights into practice. Mentally, it calms and systhesizes, and aids the transmission of neural signals through the brain. It is helpful where insomnia is caused by an overactice mind and protects against recurrent nightmares. Amethyst enhances memory and improves motivation, making you more able to set realistic goals. It can help you remember and understand dreams and facilitates the visual process.

Amethyst balances out highs and lows, promoting emotional centering. It dispels anger, rage, fear, and anxiety. Alleviating sadness and frief, it supports coming to terms with loss.

Amethyst is one of the most spiritual stones, promoting love of the Divine, giving insights into its true nature, and encouraging selflessness and spiritual wisdom. It opens intuition and enhances psychic gifts. This is an excellent stone for mediation and scrying and can be placed on the third eye to stimulate it. Sleeping with Amethyst facilitates out-of-body experiences and brings intuitive dreams. It transmutes "lower" energies to the higher frequencies of the spiritual realms.

HEALING: Amethyst boosts production of hormones, and tunes the endocrine system and metabolism. It strengthens the cleansing and eliminating organs and the immune system. An excellent cleanser for the blood, Amethyst relieves physical, emotional and psychological pain or stress, and blocks geopathic stress. It eases headaches and releases tension. This stone reduces bruising, injuries, and swellings, and treats hearing disorders. It heals dis-eases of the lungs and respiratory tract, skin conditions, cellular disorders, and dis-eases of the digestive tract. It is beneficial for the intestines, regulating flora, removing parasites, and encouraging reabsortion of water. Amethyst treats insomnia and brings restful sleep.

At a subtle level, Amethyst balances and connects the physical, mental, and emotional bodies, linking them to the spiritual. It cleanses the aura and transmutes negative energy, an stimulates the throat and crown chakras. It is helpful for people about to make the transition through death. Amethyst can stabilize psychiatric conditions but should not be used in cases of paranoia or schizophrenia.

POSITION: Wear or place as appropriate, especially as jewelry. Clusters and geodes can be placed in the environment and single points are used in healing. Place the point in toward you to draw in energy, and away from you to draw off energy. Amethyst is especially beneficial worn over the throat or heart. For insomnia or nightmares, place under the pillow. Amethyst fades in sunlight.

SPECIFIC COLORS

Violet-Lavender Amethyst has a particularly high vibration. Double terminated lilac crystals take you into beta waves. They also stimulate then calm the throat and heart chakras. Violet "flowers" bring light and love to the environment.

Chevron Amethyst is one of the best third-eye stimulators. It enhances inner, intuitive vision and outer, physical vision, and out-of-body journeys. It has powerfully focused energy that dissipates and repels negative energy. This stone cleanses the aura and aids in auric diagnosis. It has a strong healing feild, bringing harmony to the organs of the body and stimulating the immune system. It helps you to find and implement a postive answer to any problem."