Hi - Here is some of the extra information I said I'd post, I hope this is helpful rather than complicating your studies of the chakras. Warning - this post is rather lengthy.
I looked at the other links Marion posted and noticed there was a question about whether or not the chakras went from front to back. My answer to that is yes, there are chakras at the front and at the back of the body, and I'm posting a link here http://www.kheper.net/topics/chakras/index.html that shows several diagrams of what the chakras look like. You'll find when you look at the contents of that site that there are many more chakras than just 7. There are what are called primary, secondary and tertiary chakras, and I have found that there are minor chakras (or energy centers) located at every single joint in the body, including being located at each disk between the vertebrae of the spine.
A common misconception is that stones always have to be of the same color as the associated color of the chakra they're being used on. This isn't necessarilly always the case, so I'm including some information from my notes about the importance of colors and color-therapy as well as a list of conditions or requirements and the common stones that can be used for those conditions.
COLORS - the colors of stones should to be taken into account when determining which stones to use for which requirements. Color plays a very important role in our day-to-day lives, more than most people realize. Color can effect us in both positive and negative ways, and colors can be related to certain ailments or conditions that need to be corrected. Sometimes we can treat conditions associated to a particular color-group with what are called OPPOSITE or ANTIDOTE COLORS. So, this isn't all of it, but it's a start, and remember that other colored things besides stones are important. Things that we SEE on a regular basis such as flowers, or fabrics, decorations, etc., can be used for color therapy.
COLOR TREATMENTS (It helps if you make up your own little color wheel)
RED - 1st chakra color - This is a stimulating and hot color to be used to treat slow and weak conditions: depression, fearfulness, debilitation, lack of energy, spaciness or lack of grounding, low blood pressure, sluggish digestions, poor circulation, shock, anemia, impotence, frigidity, infertility, lack of menstrual flow, and after childbirth if there is weakness or much loss of blood.
Do not use red for nervous or 'red-seeming' conditions such as high fever, agitation, hyperactivity, burning ulcers, high blood pressure, red face or skin, inflammations, swellings, bad bruises or sprains, rapid heart-beat or palpitations, broken blood vessels, AND NEVER USE RED OVER THE EYES. Red is the easiest color to overdose with and can cause one to feel nervous, angry, hot, uneasy, fidgity. The ANTIDOTE colors for red are GREENS and BLUE/GREENS.
ORANGE - 2nd chakra color - This is a warm and energizing color which can be used to treat kidney weakness, constipation, muscle cramps and spasms, insufficient lactation, lack of energy, allergies, inhibition or timidity. Orange makes the best appetite stimulant.
Do not use orange for conditions of excessive sexual energy, aggressiveness, nervousness or excessive energy. The Antidote color is INDIGO.
YELLOW - 3rd chakra color - Another warm color, yellow can be used to treat digestive difficulties, gas, food allergies, liver problems, diabetes, hypoglycemia, hypothyroid, gallstones, muscle cramps, difficulty breathing, mental and nervous exhaustion, depression, lack of ambition or motivation. There are no serious contra-indications for using the color yellow, but where this color is being used a lot, I also recommend a small amount of the color violet be used together with it, just to balance it out a bit.
GREEN - 4th chakra color - Green is a neutral color. It can be warm or cool, it can be used for either warm or cool conditions, and it can be used as an antidote against any other color. This is an especially good color to use when treating cancer. It is one of the best pain-killers and is effective in treating heart pains, heart attack, high blood pressure, fatigue, difficulty breathing, for building up the immune system, for combatting respiratory infections. In fact, this color could be used on just about any ailment or condition I can think of. There is no need for an antidote color to green, but the opposite color of green is red.
PINK - This color treats negativity, tension, stress, insomnia, anger, paranoia, manic-depression, indecisiveness, low self-esteem or confidence, 'heart-break', rejection. Pink is particularly effective during the death-watch. Pink can be used to treat skin conditions, hair problems, over dryness of mucous membranes. It's good to use for getting in touch with nature or with creative talents. There is no need for an antidote color, but the opposite of pink is green/black.
BLUE - 5th chakra color - this is a cool color, the most frequently used color for healing since most illnesses are characterized by inflammation. Use blue for hyperthyroid, sore throat, inflammation, burns, skin irritations or rashes, fever, ear or eye infections, overtiredness, mental exhaustion, gum inflammations, teething, ulcers, digestive irritation, nervousness, colic, back pain, hemorrhoids, high blood pressure, toxemia of pregnancy, vaginal infections, hyperactivity, excitability, violence.
Blue should not be used to treat cold conditions such as head-colds, muscle contractions, paralysis, poor circulation, pinched nerves, pneumonia, broken bones, problems with finger/toe nails. The antidote color is Orange.
INDIGO - 6th chakra color - Indigo is a very cold, deep purplish/blue color. This helps to anesthetize or freeze severe pain. It can also relieve diahrrea or agitation and tightness of the intestines. It is quite effective against the burning pain and itch of hives,as well as helping to reduce or ease the discomfort of hot-flashes. It is used to relieve psychic exhaustion and to clean up the third eye area (6th chakra) after doing a lot of psychic work. Indigo can help to develop the psychic faculties but should be used for limited periods of time.
Excessive Indigo energy can result in egomania, schizophrenia, withdrawal, dogmatism, mental instability. Children are very sensitive to indigo energy. The antidote color is bright yellowish/orange, like the color of goldenrod flowers.
VIOLET - 7th chakra color - this a warm to luke/warm color, it can help with preventing migraine headaches, insomnia, depression, inability to make decisions, catatonia, to treat black eyes and bruises, to eliminate parasites, for baldness and dandruff. It generally has a calming effect on the emotions. Violet is the color associated with spirituality, connection with the higher self, cosmic consciousness, extra-terrestrial intelligences, astral projection, high sorcery.
Excessive violet energy beomes too hot, and can result in making migraines even worse. It can cause depression, frustration, spaciness, psychosis, confusion or a feeling that there is something you should be doing but you don't know what it is. The antidote color is yellow.
BLACK - Usually associated with the feet chakras - This is a cooling, grounding color for establishing a connection with the earth. Black can be used to create a sense of invisibility or for putting up a protective barrier against negativity in one's environment. Dull, muddy black may represent the negative aspects of the color, i.e. death, depression, evil intent - shiny black represents the positive aspects, strength, constructive power, spirituality. Black is representative of mastery of magic and occult knowledge, however, it is almost universally acknowledged as an 'evil' color. (Please note, this is not my own opinion, I personally don't think any color is evil.) Muddy black will show up in a person's aura over those parts of the body that are diseased or otherwise highly stressed. The antidote colors for black are white and all pale pastel shades.
WHITE - this color can be cool or warm and is considered by many to be the perfect blending of all the seven colors of the spectrum, and the one pure color that contains the energies of all elements and chemicals found in the sun. The positive aspects represent goodness, light, purity, peace, modesty, innocence, gaiety, happiness, pure intelligence,. White can be used to help enhance the healing properties of other colors, and can safely be used to enhance all psychic and spiritual faculties.
The negative aspects of white may be chronic weakness, fatigue, delicacy, infirmity, excessive cowardice. Many very old and frail people have too much of the color white in their auras, and this needs to be revitalized with other colors. Antidote colors would be other colors appropriate to the prevailing conditions, and sometimes just shiny black for grounding and boosting white.
GOLD is warm and can help to enhance wisdom, memory, self-confidence. It's good for arthritis and joint ailments, and is good for the eyes.
SILVER is cool and can enhance physical energy and psychic/spiritual faculties. It's a very good color for children who are slow learners.
The following is a list of common conditions or requirements and the list of stones named as recommendations is shorter than it could be. There are many other non-listed stones that would be appropriate but since there are so many minerals I've listed only the more common stones that are most easily obtained. You'll notice that many of the stones listed here can be used for a multitude of purposes (i.e. bloodstone, amethyst).
STONES TO USE FOR ...
Amethyst, apophyllite, blue lace agate, calcite, flourite, hematite, blue jaspers, lapis lazuli, malachite, moonstones, clear quartz, sodalite, blue tiger eye, turquoise, opal, ametrine, white or blue coral, white or blue star sapphire, dioptase, emerald, apatite, iolite, Tibetan quartzes, larimar stone, spirit stones (any color), moldevite, celestite.
GROUNDING / STABILIZING
Apache tears, citrine, flourite, hematite, brown jaspers, wonderstone jasper, moonstone, pyrite, rose quartz, smokey quartz, turquoise, petrified wood, pearl, tiger iron, rainbow obsidian.
STRESS / EMOTIONAL PROBLEMS
Amethyst, amazonite, apache tears, aventurine, blue lace agate, carnelian, flourite, hematite, picture jaspers, blue jaspers, malachite, moonstone, rose quartz, smokey quartz, turquoise, iolite, mica, any Tibetan quartzes, Botswana agate, spirit stones, snowflake obsidian.
ESTEEM / SELF CONFIDENCE
Aventurine, carnelian, citrine, green jasper, moonstone, bloodstone, moss agate, clear quartz, rose quartz, sodalite, turquoise, golden healer quartz, tree agate, tree jasper, all colors tigers eyes, tiger iron, green jade, red jade, nephrite, covelite, pyrite, lapis lazuli, diamond, ruby, mica, garnet, topaz, green tourmaline, iolite, Tibetan quartz, herkimer diamond crystals.
ROMANCE / FRIENDSHIP / FELLOWSHIP
Aventurine, calcite, carnelian, citrine, flourite, green jasper, lapis lazuli, malachite, moonstone, moss agate, clear quartz, rose quartz, smokey quartz, sodalite, all tigers eyes, turquoise, sunstone, ocean jasper, larimar stone, cut geodes, pink jaspers, pink chalcedony, rainbow moonstones, pink moonstones, ruby.
Aventurine, blue lace agate, calcite, flourite, wonderstone jasper, blue jaspers, pink jaspers, lapis lazuli, moonstones, moss agate, clear quartz, rutilated quartzes, turquoise, red jade, nephrite, mica, iolite, flint, silver.
INVISIBILITY OR NEGATION OF THE PERSONALITY
Hematite, opal, matrix opal, fire agate, apache tears, smokey quartz, black obsidian, pyrite, black jade, flint, iron, sea creature fossils.
PROTECTION / EXTERNAL SHIELDING
Amethyst, bloodstone, carnelian, flourite, hematite, yellow jasper, red jasper, lapis lazuli, malachite, moss agate, pyrite, smokey quartz, yellow tiger eye, red tiger eye, turquoise, alexandrite, fire agate, ruby, red coral, opal, flint, peridot, apache tears, covelite, picture jaspers, ametrine, ruby zoisite, green tourmaline, black tourmaline, black star sapphire.
PROSPERITY / GOOD LUCK
Carnelian, citrine, moss agate, malachite, brown jasper, moonstone, clear quartz, turquoise, all tigers eyes, jade, mica, ruby, dioptase.
WEALTH / FINANCIAL MAINTENANCE
Jade, citrine, yellow sapphire, flint, garnet, jet, ruby, pyrite, golden rutilated quartzes.
SEX / FERTILITY / PREGNANCY
Bloodstone, moonstone, smokey quartz, red tiger eye, carnelian, apache tears, malachite, rose quartz, opal, chrysoprase, pearl, peridot, garnet, petrified wood, pink opal.
REJUVENATION / REGENERATION
Apophyllite, bloodstone, blue lace agate, calcite, citrine, flourite, all jaspers, lapis lazuli, malachite, moonstone, pyrite, clear quartz, rose quartz, red tigers eye, yellow tigers eye, carnelian, moss agate, hematite, turquoise, peridot, red coral, garnet, amber, dioptase, iolite, herkimer diamond crystals, covelite, sunstone, ametrine, champagne zircon, champagne topaz, mica, iron, gold, silver, copper.
IMMUNITY / FATIGUE / ALLERGIES
Amber, bloodstone, carnelian, calcite, citrine, flourite, hematite, all jaspers, lapis lazuli, malachite, moonstone, pyrite, clear quartz, rose quartz, yellow tiger eye, turquoise, moss agate, ametrine, covelite.
Amber, apache tears, calcite, bloodstone, carnelian, flourite, citrine, yellow jasper, leopard jasper, malachite, moonstone, moss agate, pyrite, rose quartz, smokey quartz, sodalite, peridot, zircon, emerald.
Brandberg amethyst, apophyllite, aventurine, bloodstone, carnelian, citrine, flourite, malachite, pyrite, rose quartz, smokey quartz, red tigers eye, turquoise, lapis lazuli, emerald, dioptase, chrysophrase, rhodonite, rodochrosite, ruby, white star sapphire, moldevite, celestite, ajoite, pink ocean jaspers, pink chalcedony.
Amber, apache tears, bloodstone, calcite, citrine, yellow jasper, leopard jasper, lapis lazuli, malachite, moonstone, rose quartz, smokey quartz, sodalite, any rutilated quartzes, peridot, olivine, yellow topaz, yellow zircon, aragonite, apophyllite, yellow apatite.
MUSCLES / SKELETAL SYSTEM
Amethyst, amazonite, apache tears, bloodstone, blue lace agate, calcite, carnelian, citrine, flourite, red or black hematite, wonderstone jasper, malachite, pyrite, sodalite, red tigers eye, turquoise, moss agate, red jade, botswana agate, tiger iron, covelite, snowflake obsidian.
ARTHRITIS / OSTEOPOROSIS
Amethyst, amazonite, bloodstone, blue lace agate, calcite, flourite, hematite, lapis lazuli, malachite, azurite, moss agate, moonstone, sunstone, pyrite, rose quartz, red tiger eye, turquoise, tiger iron, ammolite, ammonite, covelite, septarian stone, copper, seashell, pearl, iron, flint, all colors rainbow sheen obsidians.
EYES / EARS / THROAT
Amber, amazonite, ammolite, bloodstone, amethyst, aventurine, pink lepidolite, blue lepidolite, blue lace agate, citrine, flourite, blue/green jaspers, malachite, lapis lazuli, moss agate, green tiger eye, blue tiger eye, turquoise, pyrite, clear quartz, watermelon tourmaline, green tourmaline, aquamarine, emerald, iolite, blue sapphire, blue star sapphire, ulixite.
SKIN / HAIR / NAILS
Apophyllite, amethyst, flourite, hematite, leopard jasper, moonstone, sunstone, rose quartz, pearl, mother-of-pearl, ammolite, pink opal.
PAIN RELIEVERS / DEALING WITH ADDICTIONS
Apache tears, amethyst, malachite, fire agate, lapis lazuli, smokey quartz, all tigers eye, bloodstone, hematite, pyrite, turquoise, clear quartz, rose quartz, smokey quartz, moonstone, covelite, ammolite, calcite, celestite, moldevite, dark colored jades, rainbow sheen obsidians, black tourmeline, watermelon tourmeline, green tourmeline, ruby, diamond, all colored star sapphires, Tibetan quartzes, garnet, rodochrosite, yellow topaz, golden healer quartz, spirit stone quartz.