💎 Gem Treatments Talk 💎 Topaz rarely comes in shades of light blue, but it surely never comes naturally in saturation levels displayed in Swiss or London Blue. Those colors are only obtainable by irradiating and heat-treating a topaz that starts far less saturated and often contains other color overtones, like green or brown. Most topazes begins near colorless and is then treated with gem science: first comes irradiation, which changes the way the crystal absorbs light and can create unwanted