Like many of the other types of cuts in stones they are called by various names, cz earrings. One reason for this is because there isn’t a standard book that has a list of all official jewelry names that a jeweler must use. It’s basically a free for all in which people call it what they want and if the phrase catches on then it’s the thing to call it. Kind of reminds me of high school!
Anyways, the emerald cut is also commonly known as the radiant cut. Now don’t get confused in between the color emerald and the cut emerald – big difference there. The emerald cut goes as far back as when George Washington was alive and the idea of jewelry making was just getting started. To bad it didn’t last very long, just like in high school it eventually lost it’s popularity. At this point like many things is when the alternate name of radiant cut came along and today it’s called both.