By Renée Newman

Blue topaz is one of the most popular gems today, but do not expect to find it in antique jewellery. The landscape of the blue topaz market underwent a significant shift following mineralogist Frederick Pough’s report of irradiated blue topaz in 1957. Natural-colour blue topaz—found in Brazil, Russia, Australia, and central Texas—is relatively rare. In the 1970s, decades after Pough’s discovery, large amounts of undisclosed irradiated blue material entered the … Continue reading Feeling blue? A guide to blue topaz