The sobriety of the black cable of the Brass Bell ceiling light enhances the golden brass finish of the borosilicate glass shade. Borosilicate glass, having a low coefficient of thermal expansion, is less sensitive to temperature shocks. A warm alliance of copper and zinc, brass is the only metal capable of imitating gold. It is noted for its colour, which varies from pink to yellow. When unlit, the shade is golden brass in appearance. When illuminated, the brass-coated glass becomes transparent, with the bulb becoming visible in a surprising hologram effect.