Maha Rishis of Maha Bharata -ancient India and sages from great civilizations in Babylon and Mesopotamia had discovered the Great Universal Scheme of Rhythm and the need of man to become an integral part of this great scheme if he is to discover his full potential as a human being. 

Gemstones as a tool to refine radiation emitted by planets
Ancient sages also have discovered that man could derive immense power to be harnessed for the fulfillment of his worldly needs and desires from the rays of the planets refined through the medium of precious stones.

Dispelling malefic influences
Even the ordinary people in this country today know the worth of gem stones not only for their intrinsic value but also as medium for dispelling malefic planetary influences.

Correct procedure for wearing gems
Before explaining the effects and significations of precious stones or metals, we wish to briefly explain the correct procedure to be followed in wearing precious stones.

The precious stone or the gem is usually studded in a ring or other ornament. No matter where and how the precious stone is used it should be remembered that part of its surface should touch the skin and another of it exposed to the atmosphere.  The upper part of the stone should be open to attract the radiation from the atmosphere and the lower part should touch the skin so that the radiation could pass into the body.

Free from any blemish
If a jewel, gem, or a stone is to give its full beneficial effect, it should be free from any defect, a spot, a crack or any other blemish.The gem should be genuine, not cultured or artificial.
Varaha Mihir, the famous Jyotish Guru of ancient India has set apart a full chapter for gems and precious stones in his celebrated work, Brihat Samhita. 

According to Vedic Astrology, there are nine basic gems: 1) Ruby 2) Pearl 3) Coral 4) Emerald 5) Yellow Sapphire 6) Diamond 7) Blue sapphire 8) Hessonite Garnet (Gomed) and 9) Cat’s Eye