TOPAZ Untreated topaz are extremely rare especially in green (the rarest), violet and red/Pink and untreated blue. Imperial Topaz was originally green, blue or pink in color and named and favored by the Russian Czars. The pink and green colored topaz had been reserved strictly for use by the Russian royal family, hence the name "Imperial." Nowadays, they use the name, “Imperial Topaz,” as a brand name for golden-orange-pink topaz coming primarily out of Brazil. Blue topaz is almost always treated with radiation but these are not. On occasion we have a treated blue but make that prominent in the title. Other colors are irradiated too. Untreated topaz of good color is extremely rare and valuable. We own the 80 ct. flawless “Ekaterina,” Russian green Topaz, the rarest untreated green topaz on the planet and one Of the most beautiful on earth, in our opinion.