Gems are used in astrology to avert the negative influence of various planets or to increase their positive effects. The use of gems has been mentioned in the Vedic literature—the Brihat Samhita, Bhava Prakash, Ayurveda Prakash, Guruda Purana and the Rasa Ratna Samuchaya.

Gems help to improve the effects planets have on us. To counter the malefic effects of a planet, one can also chant planetary mantras, perform sacrifices and worship, and give charity along with wearing the gem. These other activities also increase the gemstone’s effect.

In general, gemstones should be worn to strengthen weak planets as calculated by the astrological chart. It is best to strengthen benefic planets when they are weak. Care should be taken when attempting to strengthen naturally malefic planets, such as Saturn and Ketu, and gems used for this purpose should definitely be prescribed by a qualified astrologer.

Gems for Health

Gemstones can be used to cure diseases caused by afflicted planets, according to Ayurveda. To find the most effective gems for one’s particular illness, one should be diagnosed and appropriate remedies prescribed by an Ayurvedic doctor. To make such medicines, the gems are powdered (pishti) or from the ashes (bhasma). High quality gems can also be placed in a solution of diluted alcohol and set in a dark place for between twelve hours and seven days. The gemstones are then removed and the alcohol solution used as medicine. This gem tincture can be kept in storage; it does not quickly lose its potency. The gemstone itself is also reusable. To store such medicine, place it in a box the same color as the gem used. This will protect the tincture’s potency. The usual dosage is about ten drops in half a cup of water, and then drunk. Some authorities believe that alcohol should not be used because it is not a pure substance.

Gems can also be tinctured in water, which is considered by some authorities to be a purest system. Place a gem in a glass of water in the sun for two to four hours or overnight. If overnight, the tincture should be drunk the next day; water tinctures quickly lose their potency.

Wearing Gems

Ideally, gems should be worn on the correct finger, should be set in the correct metal, and should be the correct weight. They will have the best effect if they are also worn on the correct day and at the correct time of day. At least the installation of the gems should be performed on the correct day, and proper mantras should be chanted when they are first put on. It is best if the gem’s wearer, him or herself, chants the mantras.

It is important to clean gems before wearing them. They can be cleaned by running water over them for six to eight hours, by burying them overnight in the earth and then rinsing them with clean water in the morning, by placing them in a candle flame, or by placing them in direct sunlight. They can also be purified by being placed next to a crystal quartz.

Power of Colors

Seven colors radiate from the body: red, orange, yellow, green, blue, purple and indigo. Astrological gems are used in relation to these seven colors. Gems work by absorbing particular colors. Colors can have a subtle effect on a person’s mood, situation, behavior, and destiny. Gemstones have the most condensed form of concentrated color of all elements in the world.

The colors that we wear as well as the colors we choose to paint our walls, have an effect upon us. Bright colors tend to brighten our mood, and they indicate the luxuries in and pleasures of life. Dull colors tend to make us more somber. Shades of red represent passion and energy. Light blues and light greens represent peace and calm. White represents purity, innocence, and peace. Light colors are more conducive to sound sleep; bright or dark colors can cause sleep to be restless.

Thus each gem and each planet emit particular colors and vibrations. Negative planetary vibrations can be averted, and positive planetary vibrations attracted, by wearing gems of particular colors. Gems have stronger or weaker effects depending on the color emanated and the rate of absorption. The wavelength of the red light emanating from the Sun is the same as the wavelength of the red light emanating from a ruby. Therefore, rubies can help solve afflictions arising from a weak sun in the native’s birth chart.

The planets and colors are: Sun - Golden, dark yellow, orange; Moon - White; Mars - Red; Mercury - Green; Jupiter - Yellow; Venus - Rainbow; Saturn - Black, indigo; Rahu - Red, honey; Ketu - Purple.

Relation of the Planets

There is a gem stone that relates to each of the nine planets. These nine stones are called Navaratnas (nine gems). Five of them are categorized as Maha Ratnas, and are considered superior. These are diamond, ruby, emerald, blue sapphire, and pearl. If the better quality stones are too expensive, it is all right to wear a good quality substitute, but the higher the stone’s quality, the stronger the effect.

Prescribing a Gem

Using gemstones as astrological remedies is a complicated science, and it is best to consult a qualified astrologer before making any decisions in this regard. Wearing an incorrect gem can be severely detrimental to one’s health and happiness.There are those who think that if a krura-graha, cruel planet, is badly placed in the chart, one should not use its gemstone to improve its effects. This is because the gemstone may also strengthen the planet’s bad effects. It would be better, these experts say, to use another gem—one that would strengthen the positive planets in the chart and therefore improve one’s situation overall.

Other experts say that wearing gemstones filters out the negative rays of the afflicting planets and allows only their positive aspects to work on the wearer. Whatever one’s point of view, it is certainly not a good idea to wear a gem to strengthen an afflicted planet without having that gem prescribed by a qualified astrologer. In prescribing gems, the birth chart must be drawn to see how the various planets are positioned in the rasis (zodiacal signs) and bhavas (houses). An astrologer would then look at the position of the planets in the signs and houses, whether they are in friendly signs, are exalted, are well-aspected, or are in mulatrikona. All these things give positive effects and strengthen a chart. Besides checking the birth house chart, a navamsa chart is often also drawn and examined in Sidereal astrology.

Astrologers may also prescribe gemstones based on prashna charts, which are charts drawn up to reply to particular questions. Gemstones may be prescribed to help with specific problems addressed by the native’s question.

Things astrologers may check to prescribe a gem:

1. The lagna (rising) sign, and whether it is positively situated.
2. The mahadasha or major planetary period. Sometimes gems will be prescribed to help during a particular mahadasha, and then removed after that planetary period has passed.
3. The Moon’s position in the chart.
4. The position of the twenty-seven constellations the Moon tenants. Different gems may be worn during different constellations.
5. Then the overall chart is assessed: what planets are exalted, sign ownership, aspects, and other positions.

But beyond generalities, come the specifics. How will a particular home benefit?