Vedic astrology is also known as Jyotish, and translates from sanskrit as science of heavenly bodies. The system of Vedic astrology dates back at least 5,000 years. Jyotish astrology is based on a sidereal procession of the equinox, whereas Western astrology uses a tropical zodiac. (equinox occurs twice a year, and it happens when the plane of the earth's equator passes through the center of the sun.) The sidereal system allows for movement of the planets, while the tropical zodiac is fixed. The two systems were aligned 2,ooo years ago, but due to planetary movement, they are now almost 24 degrees apart, with the vedic system almost one full sign behind the western. This means that when a person has a sun sign of say taurus in the western, in the Vedic unless they are on the cusp, they would be one sign backwards, so they would be aries ascendant.
However, in the Vedic system, the sun sign is not considered the primary, rather the rising sign is the one that is most focussed on. Gemstones are used in Vedic astrology as the primary way of positively influencing the karmic planetary patterns, and each rising sign has its associated gemstones, which have been used for thousands of years by billions of people to bring balance, to strengthen the positive, and diminish the adverse or negative
energy patterns, assisting the person to express optimally.