The opal 5 carat price in India is calculated at around 1 gms (0.9 gms for opal stone 5.25 ratti) and is advised to individuals that have weak Venus in their horoscope or going through Shukra Mahadasha. As per Vedic astrology, it is ruled by the planet Venus(shukr) and benefits the Tula (Libra) and Vrishabha (Taurus) Rashi the most. In the USA and other Western countries, it is also famous as the October birthstone. Ranging between INR 3,000 to INR 15,000, the opal stone 5.25 ratti price depends on color, clarity, cut, and origin, besides the weight.