14K solid yellow gold genuine Alexandrite and Diamond Estate ring set. The alexandrite gemstone has been certified as genuine and measures 3.8 MM in length. Blue diamonds and baguette diamonds offset the gorgeous alexandrite and have been authenticated as genuine diamonds by a jeweler. The rings feature 35 diamonds in total. Total carat weight is .75-1. Alexandrite is a rare gemstone often described as “emerald by day, ruby by night.” It changes color from bluish green in daylight to purplish red under incandescent light. This color shift is the result of its uncommon chemical composition which includes traces of chromium, the same agent found in emerald. The unlikelihood of these elements combining under the right conditions makes alexandrite one of the rarest and most expensive gemstones on Earth.