Blue Glow In The Dark Cube can be charged again, and again with any light source. It is glass, with high quality pigment inside. It comes with a copper rolo chain. Inspired by the Tesseract cube. A great geek girl gift! Please keep in mind that some of the glowing pigments do not react to artificial light that does not produce UV. Sunlight is best, but blacklight works too. Fluorescent light will bring out some of the colors, but not all of them. Natural mineral glowing pigment needs a UV charge to bring out it’s beauty.