Gemstones are the purest and most concentrated substances found in natural form in Nature. There are hundreds of varieties in stones, greatly varying in quality and availability. Gemstones are usually used as remedial measure by wearing them. Each gem is associated with one of the planets. By having the gem in the proximity of the body, the body is effected by it's qualities. The effect of a gemstone is two fold: - it enlivens the effects of the corresponding planet in the chart - it purifies or worsens the quality of the planet it relates to The first type of effect is true of wearing or holding any object that is related to a particular planet. Wearing red clothes, driving a red car, or having red furniture will enliven Mars. The same is true for wearing a stone such as red coral. Whatever planet the object or gem is associated with, will become more active in life. For this reason alone, the gems associated with malefics are not recommended less often.

However, that planet may have very good lordships in the chart which outweighs its natural malefic tendency. For example for a chart with Cancer Lagna, Mars is the yoga karaka, ruling the 5th and 10th houses. Wearing red or wearing a red coral will enliven Mars as well as these 2 houses, and will generally be favorable. The second type of effect is dependant on the quality of the stone. A stone that is of inferior quality may enliven just that, the lesser desired qualities in the planet! A pure stone will help to "set the example" and will introduce the body and mind to a coherent expression of the planet in physical form. Just like homoeopathic medicine can stimulate the body through very small quantities of medicine, a proper and pure gem can stimulate auspicious manifestations of the planet