A 4 carat alexandrite weighs around 0.8 gms (0.72 gms for ratti) and belongs to the Chrysoberyl mineral family from where it gets its color-changing property shining green in the day and red at night. A 4 carat alexandrite ring is especially recommended for horoscopes that have weak mercury, bringing them out of communication challenges, mental weakness, and low confidence. The 4 carat alexandrite price ranges between INR 3 Lakh to 10 lakh ($3,620.08-$12,067.02) depending on color, clarity, cut, origin, and also the intensity of the color-changing effect, apart from the weight. This is the major reason why Russian alexandrite is more expensive than the rest.