Anyone who writes an article saying alexandrite has a scarcity close to diamonds demonstrates an ignorance of gems. Diamonds are not scarce. They’re merely a controlled market. They are common as dirt. Over 700 tons of gem quality diamonds have been mined in the last century. . . and the Russians are sitting on billions of carats of unmined diamonds where a meteor struck and are not mining them to keep the price up. Natural Alexandrite IS scarce.
Russia is well known for its synthetic diamonds. I suspect they have mastered the art of mimicking natural ones to the point where even DeBeers can’t dectect the difference.