Colour is the most important factor affecting the ruby’s value. Ruby hues range from orangy red to purplish red. The most valuable ruby colours are red to slightly purplish red with medium to medium-dark tone and vivid saturation so long as the darkness of the stone has a positive effect on the brilliance. Orangy or more purplish rubies are less valuable. Large rubies are more rare and valuable than comparable diamonds.
DURABILITY, TREATMENT AND CARE
Rubies can scratch almost anything, and no natural gemstone other than diamond can scratch them. In fact, non-gem-quality corundum is often used to cut and polish other coloured stones. Most natural rubies are heat treated to improve their colour. Warm,