Prescription on the basis of 'Janma Nakshatra'-the 'Birth Constellation'
In this system the prescription is based on the constellation (Nakshatra) rising at the time of birth. This system in practice has been used for prescribing gemstones with amazing accuracy. But at times it does not give desired results as this system also ignores other astrological factors during the process of prescription of stones to a native. The table below shows in ready reckoner form this system of prescription.

Gemstones (images) Name of Gemstones Ruling Planet Nakshatra Cat's Eye Ketu Aswini Diamond Venus Bharni Ruby Sun Krittika Pearl Moon Rohini Red Coral Marss Mrigshira Hessonite Rahu Adra Yellow Sapphire Jupiter Punarvasu Blue Sapphire Saturn Puhsyami Emerald Mercury Ashlesha Cat's Eye Ketu Magha Diamond Venus Poorva Phalguni Ruby Sun Uttra Phalguni Pearl Moon Hasta Red Coral Mars Chitra Hessonite Rahu Swati Yellow Sapphire Jupiter Vishaka Blue Sapphire Saturn Anuradha Emerald Mercury Jyeshta Cat's Eye Ketu Moola Diamond Venus Poorvashada Ruby Sun Uttarashda Pearl Moon Sravana Red Coral Mars Dhanishta Yellow Sapphire Jupiter Poorv Bhadrapad Blue Sapphire Saturn Uttra Bhadrapad Emerald Mercury Revathi