1.8 cm. Ruby contains strong fiery energy. It strengthens the heart, blood circulation, cleans the blood, blood flows to the eyes and thus improves vision. It activates with the help of blood circulation. It helps in the treatment of rheumatic problems, stomach ailments. Encourages, drives away negative thoughts, melancholy. It brings energy, awakens joy in life, brings flexibility, optimism and spontaneity. The necklace helps good condition, calm and thoughtful behavior, supports purposeful activity.