See our new star sign collection in 18k gold and diamonds The zodiac signs are mainly named after the constellations that in ancient Greece were within each segment of the zodiac. Each sign is associated with one of the classic elements, water, fire, earth and air. Fire and air are positive or extroverted masculine signs while water and earth are negative introverted feminine signs. Findyour diamond zodiac sign and combine with our diamond letters. Explore the collections!