historically, stones are believed to have certain properties...

amazonite - soothing, eliminates aggravation, promotes clarity, balancing
amethyst - stability, strength, and peace, spirituality, intelligence
aventurine - protects the heart chakra, reinforces ones decisiveness; success
blue chalcedony - balancing, symbolizes benevolence, enhances generosity
blue lace agate - inspiration, aides in reaching high spiritual places
blue topaz - helps one to be unburdened by arrogance and unconfined by passion, allowing one to see all things as equally important in the overall scheme of life
carnelian - stimulates analytical capabilities, precision, and inquisitiveness
cinnabar - stimulates dignity, vitality and power; assists merchants in acquiring wealth
citrine - balancing, dissipates and transmutes negative energy, memory
coral - intuition, imagination, and visualization
chrysoprase - (australian jade) instills a state of grace (the religious kind), balances yin-yang energy, aligns the chakras
garnet - the stone of health and commitment, balancing, purifying and cleansing
green flourite - cleansing, eliminates negative energy
iolite - balancing, stimulates visions, awakens inner knowledge
jade - the dream stone, stone of fidelity, inspires confidence and wisdom
labradorite - helps transform intuition into intellect, attracts strength and perseverance
lapis - enhances wisdom, expands awareness, protective
malachite - stone of transformation, facilitates insight, balancing and equalizing
moonstone - balancing, promotes insight, stimulates confidence, protects travelers
moss agate - emotional balancing and strengthening, improves ego and self-esteem, leads one towards efficacy in all pursuits
mother of pearl - stimulates intuition, sensitivity, imagination, and adaptability; wealth
opal - strengthens memory, aids with creativity, helps one utilize intuition
pearl - brings truth, self reflection, signifies faith, charity, and innocence
peridot - lessens anger and jealousy, inspires happiness
peruvian opal - inspiration, memory, creativity
pietersite - supports courage and tenacity, grounding
pyrite - acts as a shield from many forms of negative energy, is protective and helps to keep-away all forms of negative vibrations
rainbow obsidian - brings light and love into ones life, as well as gratification and enjoyment
raspberry quartz - clears and activates the sever major chakras
rock crystal - balancing, clarity, harmony, purifying, protecting, strength
rose quartz - calming, removes negativity, promotes love, compassion
rutilated quartz - assists in problem solving, harmonizing
silver - balances, increases perception, enhances properties of other stones
smokey quartz - tends to penetrate and dissolve energy fields which have been generated from negative thought forms, anger and resentment, self esteem
sodalite - eliminates confusion, enhances truthfulness in emotions
tiger eye - balancing, awareness, soothing enhances psychic abilities, creativity, health/well being
turquoise - excellent for spiritual attunement; provides protection; heals the spirit, providing a soothing energy and bringing peace of mind
unakite - balancing, brings one's consciousness to the present, reconciliation

  all info on stones from love is in the earth, by melody