Luminous Sapphire - Briolette CollectionThe Luminous Sapphire fountain pen glows beautifully in a dark and semi dark after an hour exposure to light. A sustained vivid deep blue glow lasts for up to 12 hours, fading over time. The fluorescent luminous paints used in the pen are completely free from radioactivity and any potential hazards. Long facets covering the pens body gives the pens specific shape that prevents it from rolling and enables the true color and brilliance of the material