Based on an individual's sidereal horoscope, either a single gem or a combination of compatible gems is advised to be worn to harness beneficial planets or counteract harmful planets .Gemstones have stronger effects if they touch the skin. Hence rings made according to Vedic system are kept open below so as to bring gem in direct contact with skin. Gems also enhances effects of herbs e.g. red coral enhances effects of aphrodisiac herbs. Students are taught to prescribe specific gems for specific disease with mantra & its detail methodology which increases potency/power of gems.