Chakras are physical centers of energy located at the midline of the body. There are seven chakras, and they govern our psychies. The chakras located on the lower parts of our bodies influence our instinctual side, the chakras located on the higher parts of our bodies influence our mental side.

Gemestones are associated with the seven chakras for their colors and meanings. We use the following gemstones:

First / Root Chakra
Also referrred to as base chakra, this first energy center is found at the base of the spine. The activity of this chakra influences our sense of security and overall well-being. The Root Chakra links us to the physical world and the physical body. It is the foundation of energy. Garnet - is a protective and grounding stone which balances the energy flow and provides strength and vitality and gives us courage to take on unfamiliar situations.

Second / Sacral Chakra
Also called the Orange, Splendic or Sexual Chakra, a well-functioning second chakra influences one to maintain a healthy yin-yang existence. Carnelian - eliminates feelings of inadequacy and low self-worth, promotes feelings of self-security and self-protection. This stone is especially good for recovering after a rejection and it promotes harmony within ourselves.

Third / Solar Plexis Chakra
This energy center is the foundation of our personality. It radiates the characteristics of fire - with the qualities of expansiveness, warmth, and joy. When the energy of this area is unrestricted in its flow, it brings a balance and can make a person more confident, caring and more in touch with their higher self. Citrine - is associated with the formation of the personality, feeling, being and the combining of spiritual and earthly aspects.

Fourth / Heart Chakra
The Heart Chakra is the center from which feelings of love come. It is also associated with happiness, hope, respect, compassion, understanding, and generosity, and with loving oneself in a sincere, non-egotistic way. This is also the chakra through which we connect with others whom we love or have affection towards. Green Aventurine - is a balancing stone for the heart chakra. The stone encourages calmness and positivity and helps to release emotional pain in a gentle and effective way. Emerald - Brings security in love. It allows access to the secrets we hold in our hearts, and heals and activates our hightest heart's desires.

Fifth / Throat Chakra
This chakra is our will center. The healthfulness of the fifth chakra is in relation to how honestly and effectively we express ourselves. Chalcedony - stimulates creativity, helps us communicate and listen better and helps with self esteem.  Tanzanite - activates the throat chakra for clear communication of one's highest truth.

Sixth / Brow Chakra
Also called third eye, this chakra helps us think clearly and have a clear vision. This chakra allows us to integrate our intelligence with our intuition and allows us to trust the truth. It is the seat of understanding that affects how we see the world we live in and how we make sense of what is being perceived. Balancing this chakra can help remove confusion or indecision and increase the ability to see clearly. Iolite - The energy of Iolite helps to recognize and release discord from our lives allowing for progression toward illumination. It also enhances psychic awareness.

Seventh / Crown Chakra
Also known in Sanscrit as "Sahasrara", meaning "thousandfold", this chakra is often represented by a 1000-petaled lotus, which symbolizes the infinite nature of this chakra, connecting us with the Divine*. The 7th chakra is located at the crown of the head and serves as the crown of the entire chakra system, symbolizing the highest state of enlightenment. This chakra gives us strength in wisdom. The fundamental element of the 7th chakra is thought and cosmic consciousness. The mind creates our belief systems that control our thoughts and actions. Amethyst - brings stability, peace and balance, connecting the physical to the spiritual.

*Note that Devine can mean God, or any other higher power. I once read something, that if you weren't comfortable with God meaning the Divine, just think of God as meaning "Good Orderly Direction".

Ohm/Om
According to Hindu thought, OM is the primordial syllable which represents the ultimate reality of pure consciousness or brahman. We chant OM to clear and focus the mind during meditation - it is the
beginning and end of all mantras.

Study more about chakras online. There is a wealth of information. I particularly like http://www.magickalmind.com/chakras.htm.