Few Points on The Science of Vedic Gemology

A person's karma account is the account of the person's past life deeds. This account is known by reading the chart of the person. Vedic astrology deals with nine planets. The chart has these nine planets indicated on it, which were present in a particular position in the heavens at the time of the person's birth. The planets have a deity, a person who is the personification of the planetary mass. Just as in the olden days, say, the Duke of Suffolk would be simply called Suffolk, he was the personified representative of that land, i.e., the land and the human were one inseparable being. Similarly, an ambassador is also known as the plenipotentiary for his state. Thus, the divine beings who reside on those planets are the plenipotentiary for those respective planets.
A gem is the personification of that planet’s lord and the planet as well. Thus the gem is linked to this divinity (the personality bearing lordship over the respective  planet).
The planets are agents to heal or edit the karma account, to add things to it or subtract things from it. The wearing of the gems that the astrologer prescribes causes for these deities to be pleased with the wearer and they reward the wearer with that which the astrologer has indicated for that specific gem. The ancient Vedic astrological science mentions gems as remedies which directly add or delete the karma account itself. This is why astrology is the highest and most potent material science of all the ancient Vedic sciences which deal with the universes i.e., activities contained within the universes, in short, universal phenomenon. Since there are nine planets, there are nine gems in Vedic astrology which correspond to these nine planets.
The gems are the celestial instruments which cause for the planets to do the needful according to the client’s wants and needs. Thus the power of the gems is to edit the source of all things, the karma account of the client.
A computer program or AI or a machine, has not ability to reason neither it cares for you, it is a dead object. It will do whatever you ask it to do. As it is said about the nature of AI: if you ask an AI to reduce the traffic of the world, one of the options that it will consider and perhaps execute is to terminate all human life from earth since that is what it deemed to be the best and most viable option to reduce traffic from the roads. This is not how the instruments of astrology, i.e., the gems work. They are persons who reason. Thus, one should never verbally insult gems because they may take an offense and stop functioning or curse the wearer. They are not AI, they have RI, real intelligence. RI is a concept either not known to the scientists of the 21st century or they have not disclosed it to the public yet. Thus a gem is that RI, which shall never ruin its wearer at the cost of the wearer's desires. It will regulate the flow of the objects/statuses that the wearer wants in his life with a holistic vision of the past, present and future. E.g., if the astrologer prescribes a certain wealth giving gem to the client, the gem will certainly give wealth. However, if there is a life insurance policy on a beloved person in the client's life, the gem won't kill that beloved person and cause for the money to come to the client. The gem can understand this - it reasons and acts in such a way that won't do harm to the client because it can calculate what the client really wants, what is the best for the client and how to best achieve it. Thus the gem, unlike the dead AI of the world, cares for the client and reasons to do good for the client.
A good number of the species of life in the universe are capable of being simultaneously present at more than one point in the universe. The deities bearing lordship over the planets are present in their respective gems. They are non-human, mostly humanoid individuals, they couldn’t careless for punishing a human who goes against the universe’s laws. Similarly for them to confer say, something like peace of mind, a good husband, motherhood, good health for one’s children, a few billion dollars, etc to a human of earth, is a nano-scopic fraction of their full potential, for that they also couldn’t care less for not giving that as well. It works both ways.
The planet or to say the divinity appointed to that planet controls a certain relative segment of the spectrum of the karma account of any human of earth. The astrologer reads the chart and determines which part of the karma account is causing what problem or to say, what part of the karma account is in need of fixing to accomplish some objective or gain some thing in the world (as the client needs or wants). This is done by appeasing the planet's lord. This is done by the medium of the gems.
The gems are not ordinary gems that come from a jewelry-shop. They are technically called Vedic astrologically authorized gems. An Vedic astrologer knows people who are connected to the mines - the mine owners, miners, gem sellers, etc from generations after generations altogether. These people who can understand with their abilities the difference between astrologically viable gems and the regular gems which are meant for the purposes of jewelry/fashion. Thus the gem mine owners and the procurers are important for they know with their supernatural abilities how to select a gem for the purposes of Vedic astrology. Such individuals work closely with the astrologer.  The final selection is done by the astrologer because very gem is essentially unique and it, ‘calls unto the astrologer for it to be selected for a certain chart’. Thus it is not wise to walk into a jeweler’s shop and get a gem and start wearing it. It is a far more complicated science than that.
The astrologer who is prescribing the gem is, for a lack of a better choice of words, supernaturally linked to the chart of the client and to the gem which he prescribes. Thus the astrologer’s will has a major say in what functions of the gem will be, apart from their natural functions. This is the same as with Ayurvedic doctors or Vastu experts. If the patient insults the Ayurvedic doctor, the medicines prescribed by the Ayurvedic doctor, at best don’t work or at worst have a negative effect. The Vastu science related remedies do not work if the the client insults those remedies or the Vastu expert who prescribed those remedies.
Thus the gem that you get is like a friend. Yes, one may choose to pray to it, if one feels that type of a fervor. Indeed the gem can actually say things to its wearer either directly or from within the heart, they are indeed celestial living beings. As the months and years go by, the gem becomes one with it wears and they are a team. It fate is tied to the wear’s fate.
The chart determines the quality and carat value of the gem. This may differ for different charts. The effects of the gems are classified into primary, secondary and tertiary: Primary is specific for the person’s chart, secondary is gem specific and tertiary is money since all gems are also partial representative of the goddess of wealth and fortune, Laxmi. Thus all gems on their own give money to the wearer. It is seen that the basic return on investment, to use a modern phrase, is ten times the investment made.
Gems are to be worn in a specific metal. They can be worn in three ways: as a ring, as a pendant or just kept in the client’s home. Gems are to be worn on what is known as a muhurta, an astrologically approved time. The astrologer gives this time. They are to be worn by the client after the performance of a certain small and very easy to perform ritual. The astrologer will teach the client this ritual. Before the gem is given to the client the astrologer performs upon the gem a certain Vedic ritual, with Vedic mantras in the Sanskrit language. This, in Sanskrit, is known as the pranaprathistha ritual or the life-force-inviting ritual. It is by this ritual that the gem is rendered semi divine because the astrologer has caused for or to say invited the specific celestial divinity to come to the gem to reside in it. It is from that moment on, the concerned divinity resides in the gem.
Gems are to be passed from parent to child, so on and so forth. Coral and pearls last for a few hundred years for they dissolve bit by bit with water due to the fact that they are calcium products. The rest of the gems may last for thousands of years. Thus a gem is a dynastic investment. If the parent gets a gem from his prescribing astrologer and in the due course of time if the parent passes away, and if the same gem happens also to be prescribed to the child, then child need not purchase any other gem, so on and so forth for generations to come. The astrologer is to be consulted for the gems to be passed to other members of the family. However, the general rule is that they are to be passed from parent to biological child.
These three paragraphs indirectly answer the irreverent question of the mundane mind - if the gems are so wonderful, then the persons who deal in the gems, who store them in their homes must be billionaires by now? The gems need to be ritually consecrated by the prescribing astrologer, ritually worn according to the various instructions of the astrologer, reverentially treated by the wearer, it is then that the gem becomes enclosures for the universe’s divinities to reside in and work their blessing through and not other wise. The applier of the science, the teacher of the ancient technical knowledge, the guru, the master, the spiritual master, etc are the via mediums for a certain divinity to act in some mundane instrument. The divinity cannot be accessed without a connected being. This is a recurring theme in all the Asian paths which aim at raising the self to a state of higher self, be it karate, Kung-fu, Jujitsu, pranic healing, Feng Shui, Chinese herbal medicine, Tai chi etc - there is no question of these paths/processes being practiced out of a DIY book. They all require a master to infuse the technique or the artifacts with certain, ‘blessings’. The principle remains intact and is taken from the Vedic sciences. Only a person in fatal ignorance of the culture that goes along with these ancient sciences would think that a master and his blessings are not needed.