Zircon (Zirconia) often known as American Diamond is used as the substitute of real diamond. The laboratory name of Jerkin is Zirconia. It is recommended to those people whose Sun-Sign, Moon-Sign or Lagna (Ascendant) lordship is under planet Venus. People with the sign of Taurus and Libra are specially suggested to wear a Zircon. Where as the actual stone related to Venus is a real diamond. But as Zircon has the properties almost similar to a diamond, many astrologers and Vedic professionals recommend Zircon instead of real Diamond. Zircon is far cheaper than real Diamond and so that is the other reason behind recommending it.