These are lab created rubies produced in the Soviet Union back in the 1970s or 1980s, cut from an old collection. Some of the original lab ruby rough in this batch was grown from the pink pure chromium formulas originally intended for lasers, but others are definitely using the jewelry ruby formulas instead, which add codopants for richer red color (some of the magenta rubies seem to have added titanium, for instance). These appear to be grown mostly or all through the flame fusion method. They are great for any lover of science, history or the color pink.
