How to choose Gems?

Gemstone selection is a technical subject with specialization. Due to little knowledge and misconceptions, the selection of the wrong gemstone proves to be harmful for the person, so it is necessary to take full care in the selection of gems. Here are some such formulas, which are very useful in the right selection of gems:
1. There are many basis for the selection of gems such as; Gemstone selection on the basis of zodiac, Gemstone selection on the basis of Ascendant, Gemstone selection on the basis of solar month, Gemstone selection on the basis of lunar month, Gemstone selection on the basis of Bhagyank or Radix, Selection of gems on the basis of palm And so on. In these bases, it is more scientific and auspicious to select a gemstone on the basis of the Ascendant Kundali, so the gemstone should be selected on the basis of the Ascendant. On this basis, the selection of auspicious gems always gives auspicious results, but the selection of gems on other grounds is not necessary to give auspicious results.
2. While selecting the gems on the basis of the Ascendant Kundali, the gems of the sixth, eighth and twelfth lord should not be worn often. If a planet is the lord of triangle or center being in the sixth, eighth or twelfth house and is weak in an auspicious position, then the gems of the owners of the above houses can be worn.
3. The gemstone of Ascendant is always auspicious for the native.
4. The gems of Panchmesh and Bhagyesh are usually auspicious for the native.
5. Gemstones of second lord and seventh lord should also not be worn often.
6. A belief is also prevalent in relation to the selection of gems that if a planet is weak and in inauspicious position in the Ascendant Kundali, then it should be worn to make it strong, because strong planets give auspicious results. In practice this is not true in all situations. That is why gems of inauspicious condition and weak planet should not be worn often.
7. It is generally believed that the Mahadasha or Antardasha is going on, the gemstone of that planet should be worn, but this belief is not correct. The planets of inauspicious and inauspicious condition give inauspicious results in their Mahadasha and if one wears their gems, then there will be an increase in inauspicious results, therefore, in the Mahadasha and Antardasha of Yogakaraka Bhaves, their gems should be worn.
8. It is also a popular belief that if a planet is moving in an auspicious position during the transit, then its gemstone is also worn, but this is not a principle that gives favorable results in all situations. If a planet is in an auspicious position in the transit, but it is in an inauspicious position in the Ascendant horoscope or is the owner of inauspicious houses, then wearing a gemstone of such a planet can also give inauspicious results.
9. Gemstones of two mutually enemy planets should not be worn together.
10. Gemstones give results related to the karakatva of the planet concerned and the karakatva of the house related to the planet, so to get results in a particular area, the respective planets and houses should choose gems on the basis of karkatva.
On the basis of some of the above mentioned major sources, the selection of suitable gems can be done from the selection of gems. It would be preferable to take advice of expert and experienced astrologer in this regard.