Eastern Gemology

Astrological Remedial Measures
Birthstone by Sidereal System
Brilliance
Carat-Weight and Size
Clarity
Cleavage
Color
Constellations and Gems
Cut and Polishing
Finger To Wear On
Fire
Gem Substitutes
Gems for Health
Gemstone Chart
Hardness
Installation of Gems
Navaratna Ring or Pendant
Planet's Relations
Positive Effect Testing
Powers of Colors
Prescribing a Gem
Purchasing Gems
Refractive Index
Ring Settings
Specific Gravity
Stability
Synthetic and Treated Gems
Toughness
When and Where to Wear

Gems are used in Eastern 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.

The gem therapy described in this book is based on the Vedic (Indian) or sidereal system of astrology.Each sign of the zodiac is ruled by a planet, and each planet gives off a cosmic vibration and rules, or is related to, certain gemstones. The gems absorb or reflect the planets’ vibration, or rays. Wearing the proper gem can increase a planet’s positive effect on the wearer because the gem acts as a filter that allows only positive vibrations to have influence.

Gems surround their wearer with an electromagnetic field. If a person is receiving a planet’s negative rays, wearing the correct gemstone can counteract those bad effects and allow only the planet’s positive effects to work on the person. Wearing a gemstone to counteract the malefic effects of a planet is like carrying an umbrella to avoid getting wet; the gemstone actually deflects a planet’s negative rays.

It is important to note, however, that wearing the wrong gemstone can have a negative effect on the wearer. Wearing the wrong gems short-circuits the subtle body’s energy fields. Thus physical or mental problems may result. Great care should be taking when using a gemstone of a naturally malefic planet to counter act its bad effects, as instead, it may increase the bad effects of the malefic planet.

To have maximum effect, the gemstone chosen should be of good quality. The better the gem’s quality, the more powerful its effect. Do not wear cracked or chipped gems, as they can have a very detrimental effect. Thoroughly inspect gems for defects before purchasing them.The gem’s size is also important. It is best that a precious stone be at least one carat; two or more carats are better. The minimum size for gems is determined by the type of gem. The less valuable the gem, the larger the stone should be to have the full effect.

It is sometimes not advised to wear gems that magnify the strength of planets already benefic to the wearer. The gem may make the planet’s effect more powerful than the wearer can bear.When choosing to wear a gemstone, it is important to consider one’s overall astrological chart and to understand the synergy between the various planets. It is best to have a qualified astrologer prescribe the gem. Sometimes more than one gem will be prescribed. Gems sometimes have more effect when worn on one day than on another. To receive a gemstone’s effect, the gem must actually be worn; simply owning it is not enough.

Astrological Remedial Measures
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.

Planets	Primary Gemstones	Secondary Gemstones	Zodiac Signs
Sun	Ruby	Red Spinel, Red Garnet, Red Zircon	Leo
Moon	White Pearl	Moonstone	Cancer
Mars	Red Coral	Carnelian, Pink Coral, Bloodstone	Aries Scorpio
Mercury	Emerald	Green Jade, Peridot, Green Zircon	Gemini Virgo
Jupiter	Yellow Sapphire	Yellow Topaz, Citrine Quartz	Sagittarius Pisces
Venus	Diamond	Clear Zircon, Quartz, Clear Sapphire	Taurus Libra
Saturn	Blue Sapphire	Lapis Lazuli, Amethyst	Capricorn Aquarius
Rahu	Hessonite Garnet	Golden Garnet, Orange Zircon, OrangeGarnet
Ketu	Chrysoberyl Cat’s Eye	Other types of Cat’s Eye Tiger Eye, Beryl

 Installation of Gems
1. First wash the gem in water (if possible Ganges water).
2. Then wash the gem in milk.
3. Then wash the gem again in water.
4. Then place the gem on an altar or sacred place before a picture of the deity of the planet that is related to the gem being installed. For instance, the gem should be placed before the deity of Surya or a yantra for the Sun if the planet that the gem is for is the Sun.
5. Incense should be offered.
6. The mantras for the planet should be chanted.
7. The ring should be placed on the hand.

Testing for Positive Effect
It is usually best to test a gem before wearing it. Some gems are unlucky or not auspicious to wear, even if they are flawless. It is best to first test gems by placing them under your pillow at night, or wearing them on your arm wrapped in a cloth of the same color for three or four days. If the gem has a bad effect during the test period, it should not be worn. Blue sapphire should especially be tested, as the wrong stone can have a very negative effect.

Purchasing Gemstones Overseas
It is important to purchase gemstones from a reputable shop. The difficulty lies in being able to distinguish a reputable shop from a disreputable one. Before making any purchase, go to several shops and expect straightforward dealings.

The biggest mistake a person can make when purchasing gemstones overseas is trying to negotiate too good a deal. Something valuable will not be sold for nothing. It is unlikely that a normal buyer will gain an advantage over a professional gem dealer. If you think you have struck too good a bargain, question the quality of the stone you are purchasing. In Southeast Asia there is no shortage of con men.

If someone seems too friendly and helpful, especially if you have met him on the street, be especially careful. Even if this person takes you to a reputable shop, his commission will be fixed into the price you pay. Such persons often receive a healthy commission, and you, the buyer, will find yourself paying up to fifty percent or more than you would have paid normally. Remember the old saying, “Too much devotion is the sign of a thief.” Be just as careful with tour operators, who also often receive commissions for introducing you to particular shops.

A general rule: the closer you are to where the stones are mined, the better chance you have of being cheated. There is more of a likelihood that synthetic stones are for sale along with the real ones. Unless you know the difference, such places are better avoided.

A common scam: “A special government tax has been waived for the next few days. Buy now while the price is right!”Another scam: You are told that you will be able to resell the gems you are purchasing at home for a huge profit. Or, you are told that you are receiving a wholesale price. Be extremely careful of those who make such statements. If such huge profits were available, these merchants would be making them themselves. Written guarantees mean nothing.

Prices of Gems
A gem’s price is determined by the four “Cs”: carat (weight), cut, clarity, and color. Another major factor is the buyer’s preferences. If a gem is fashionable, its value will increase. Another factor affecting price is whether the gem is common or rare. Whether a gemstone is natural, synthetic, or imitation will affect the price, as will supply and demand. Often speculation can drive the price of gemstones up or down. If a new diamond mine is discovered and the supply uncontrolled, the price of diamonds will drop. Only flawless, well-colored (or colorless) gems should be used for astrological purposes. Only ten percent of natural gems fall into this category. After flaws are ruled out, the color should be judged. Flawless gems are difficult to find. Still, they are worth seeking out, because their effect is most positive. It is definitely better to pay more for a flawless gem than a flawed one. If a gem has too many flaws, it should not be purchased at all.

Carat—Weight and Size
Carats are the unit of measurement used for selling gems. A carat is one-fifth of a gram. 5 carats =1.0 gram =0.035 ounce. 141.75 carat = 28.35 grams =1 ounce.Usually, as the weight of a gem increases, so does its value. The value does not usually increase proportionate to the increase in size, because larger stones are rarer and thus more valuable. The price of diamonds, rubies, and emeralds increases greatly with an increase in their weight, because large varieties of these gemstones are rare. For example, a one-carat diamond may cost about $1,000; a two-carat diamond will usually be more than double that price, around $3,000. Aquamarine, topaz, and rock crystal do not increase as much in value as their carat size increases, because large crystals of these gemstones are more common.

When you are shown a gem, you should be able to see its weight. If a gem is cut too deeply, much of the gem cannot be seen. The gem may also be too dark. If the cut of the gem is too shallow, it will lack brilliance and have a flat, washed-out look. If a gem is cut properly, it will look good from any angle.  

Color
A gemstone’s color is a big factor in its price. Colored stones are usually more valuable than clear ones, except for diamonds. Some gems are fixed in their color. Ruby means red, and emerald means green. Sapphires can be any color but red, but blue sapphires are considered the most valuable, along with the pink-orange “lotus flower” variety (due to their rarity). The rarity of a particular color of gemstone is an important factor in determining its price.

A good colored gem should not be so pale that it is hard to see the color, or so dark that it appears black. A gem’s color should be uniform, not blotchy or stronger in one spot than another.Trust your judgment when looking at gem color. Usually the brighter, more vivid and rich the color, the more valuable the gem. Ask to see a range of colors, and notice the differences.

Preference is quite personal. Look at the gems in a variety of lights. Some gems look great in daylight but do not look good under artificial light, and vice versa.

“Fire,” the fiery flash in a gem, often increases its value. Fire is caused by refraction, which is the bending of light inward as it enters a denser substance. This is normally seen in the refraction in water, which makes a stick seem to bend under water. 

Clarity
Clarity refers to the clearness and clean look of a gem. It is measured by lack of inclusions, cracks, or flaws on the surface or within the gem. The clearer the gem, the better. Inclusions are mineral grains that can be seen, fluids within the stone’s body, or bad crystal features, such as twinning.

Often, gemstones with cloudy inclusions and air bubbles can be clarified by using heat treatment, but gems treated in this way are not good for astrological use.

How many flaws are acceptable in a gem changes from gem to gem. A good emerald will almost always have some inclusions, and a flawless emerald is often suspect—it may be synthetic. Aquamarine should not have flaws, or very few.Sometimes inclusions can make a gem more attractive, such as with star stones—star sapphires, cat’s eyes, feldspars, and rutilated quartz.Only glass or a highly superior gem is free of inclusions visible to the eye.

To judge a transparent gem’s clarity, hold the gem in thumb and forefinger up to the sun and allow the sunlight to pass through the gem. If the gem is opaque or semi-translucent, it is flawed. These gems should not be used for astrological purposes; they will have a negative effect. Pearls, coral, jade, and agate are the only translucent gems considered to have a positive astrolgical effect. Transparent gems give one a better look at the quality of the gem.   

Cut and Polishing
Gems are cut and polished in a variety of ways. The preferred cut for a diamond is the brilliant cut, while the preferred cut for precious opal is a domed solid. Some gems are even carved. A good cut increases the value of a gem; a poor cut reduces its value.

Transparent gems are faceted (a facet is a flat, polished face). This process involves cutting with an abrasive (usually diamond) saw, grinding the gem, then polishing it. How a stone is cut affects its brilliance.

Cut can be judged by shape, type, proportion, and symmetry. Diamonds are usually cut by the brilliant cut because this cut makes the most of their high dispersion. The cut has almost sixty facets, which increases the fire or refraction in a diamond. In a diamond, the light is refracted so strongly that it is trapped inside and reflected before it emerges again. The value of diamonds increased greatly in the 1920s when the brilliant cut was developed. Like a diamond, white zircon and colored cassiterite also have strong fire, and therefore benefit from the brilliant cut. 

Hardness
Hardness is the measurement of the strength of a gem’s chemical bond. Each mineral is given a number to indicate its degree of hardness.

Hardness tells us how resistant a gem is to being scratched.Gems are measured according to Mohs scale from 1 (softest) to 10 (hardest). Minerals with higher numbers can scratch minerals with lower ones. A diamond is the hardest mineral, and receives a 10 on Mohs scale. The difference in hardness between one number on the scale and another is not proportionate. A diamond receives a 10 and corundum a 9, but diamonds are four times as hard as corundum.

Gems softer than 7 on the scale have a tendency to scratch when set in rings. Most quartz includes some dust, which has a hardness of 7. Therefore gems with a hardness less than 7 tend to become scratched by the quartz in dust.

Mohs scale: 1–talc; 2.5–fingernail; 3–copper coin; 4–fluorite; 5–apatite; 5.5–glass; 6–orthochlase feldspar; 6.5–steel: 7–quartz; 8–topaz; 9–corundum; 10–diamond.Go To Top

Stability
Stability is judged by how well a gem will stand up to chemicals or deteriorating substances. Opals contain water, and may lose stability in dry air; they may crack due to loss of original volume.

Pearls are damaged by alcohol, perfume, and acids. Some amethysts and kunzites can fade in sunlight. Porous gems such as turquoise can become discolored by skin oils.

Toughness
A gem’s toughness is based on how well it resists cracking, chipping, or breaking. Crystals often have a plane of weakness, or a cleavage.

Diamonds, which are the hardest mineral, are not actually so tough due to their octahedral cleavage planes. Diamonds may break if dropped or struck.Topaz has a hardness of 8 but is also not so tough. Topaz has one perfect cleavage, which makes it hard to facet. Some gems have an internal stress, which lowers their toughness. Opal can chip easily if hit sharply.

Nephrite Jade has a hardness of between 6 and 6.5, but it is the toughest gemstone because of its strong, interlocking fiber crystal.

Pearls have a hardness of 3, but it is tough; they do not easily break when dropped.

Luster
Luster is the light reflected from the gem’s surface. Some stones flash like the sun, while others have a subtler, softer luster. To have a high luster, the gem must have a smooth surface and be highly reflective. Polishing gems help improve their luster.Diamonds have the brightest luster. They have an adamantine or hard luster. Most other gemstones possess a glassy or vitreous luster. Quartz is a good example of such a shine. The luster of turquoise is softer.   

Brilliance
Brilliance is the reflection of light from within a gem. A brilliant gem is described as being lively, or having life. A gem’s brilliance depends on its refractive index and upon the way it is cut. A gem’s sparkle is counted as its brilliance.

Refractive Index
The Refractive Index (RI) measures the velocity of light traveling through the gemstone, and how that gem refracts the light that enters it. Refraction is created when the speed of light changes as it moves from air to some other form of matter. A faceted gem will refract back from within itself light that enters it. When light enters a gem, it changes course and is slowed down (refracted).

An instrument called a refractometer measures Refractive Index. It measures the angle that light bends in a gemstone.

The refractivity of a gem is higher in the more dense stones. The most refractive gems, diamond and sapphire, are denser than most gems. All gems except ones that have high symmetry (such as cubical stones) have two or three refractive indexes. 

Difference In Light
The light in which one views a gem can make it appear differently. The blue of a sapphire will look bluer under a fluorescent light, because fluorescent light contains many waves in the blue range. A ruby viewed under a fluorescent light will appear weak and have a muddy red color.

A blue sapphire looks best when viewed in strong sunlight in the summer or in the tropics, or under a strong fluorescent light. Winter sunlight will make it appear dull. If it is cloudy the gem may appear a grayish blue.

Specific Gravity
Density is measured by Specific Gravity. Specific Gravity is the weight of a gem compared to an equal volume of water, which is equal to the value in grams per cubic centimeter.

The density of a gem can be measured by weighing it in air and in water. Gems can also be sunk in liquids of various densities. If there are two gems of the same size, the one with higher density will appear heavier when held.   

Cleavage
A cleavage is a weakness in a crystal that tends to break along a certain plane. When there are cleavages in gemstones, it can be difficult to cut a face across them. Some gems don’t have cleavages. For example, quartz gems break in curved fractures. Fire

Fire is the play of color in a gem. Dispersion causes fire in a gem. The colors that make up white light bend to different degrees during refraction. As they pass through a gem, they separate into the colors of the rainbow. Fire is usually seen only in clear gems, because the natural color of other gems will cover this phenomenon.

The degree of dispersion varies with each gem. In two different gemstones of the same size and cut, the one with the greater dispersion will show more colors. Thus a diamond has a higher quality fire than a quartz gem. 

Synthetic or Treated Gems
A synthetic gem is a manufactured equivalent of a natural one. Such gems are manufactured in laboratory-controlled conditions, and are useless for astrological purposes.

There are different kinds of synthetic gems. An imitation gem resembles a natural gem, but has a totally different composition.

A treated or enhanced gem has been changed chemically or physically. Gems are often heated or irradiated to enhance or change their color, or to improve their clarity. Some gems are enhanced chemically by dyeing, bleaching, waxing, adding plastic, or oiling.

Some forms of enhancement are considered respectable in the gem business. For example, heating blue sapphires bring out their blue color. Such enhancements permanently alter the gem. Jewelers are required to inform customers about enhancements, if the customer inquires.

Dying is common in the gem business. To test whether or not a gem has been dyed, rub the stone with a cotton ball dipped in fingernail polish remover (acetone). Acetone will dissolve the dye and it will rub off onto the cotton ball.

Most rubies and sapphires are heat treated to improve their color because treating increases the sale value. Amethyst, spinel, topaz, peridot, garnet, citrine, and tourmaline are also frequently treated. Since jewelers are usually good at what they do, it is difficult to tell whether gems have been treated.

Once a gem has been altered, it greatly reduces its astrological value. Great care should be taken, therefore, to purchase untreated, high quality gems. 

Gem Substitutes
There are two types of man-made substitutes, synthetics and simulants. A synthetic gem is made of exactly the same substance as the natural gem, but it is grown in a laboratory. It can sometimes be difficult to tell a natural gem from a synthetic one. Natural stones often have inclusions, which help with identification. Synthetics sometimes have lines or bubbles by which they can be identified.

Occasionally, a substitute substance or gem may be passed off as the real thing. For example, a cheaper gem may be substituted for a more expensive one—citrine quartz can be substituted for the more precious topaz. Such substitutions are fraudulent.

Simulants are not composed of exactly the same substance as real gems, but when one examines them, they appear to closely resemble the natural stone. Cubic zirconia (zirconinum oxide) highly resembles a diamond and may be sold as such. Imitation gems are often made of glass, plastic, or a combination of two (doublets) or three (triplets) substances. The parts may be imitation or real.

Constellations and Gems
Each constellation is ruled by a particular planet and is related to a particular gemstone: 

Navaratna Ring or Pendant
The Navaratna ring or pendant contains all nine planetary gems. Substitute gems should not be used in such settings, and substituting for the more expensive stones should not be necessary because each gemstone used is actually quite small. All the gems should be real and flawless. The following gems are to be set in a Navaratna arrangement: diamond, emerald, ruby, pearl, coral, cat’s eye, sapphire, topaz, and hessonite.A Navaratna ring is believed to bring happiness, prosperity, honor, fame, mental peace, long life, and wealth. A Navaratna ring will enhance the good effects of any planets in their own signs or in signs of their exaltation.

Copyright ©2001 John Howley and Spiritual Guides