Glow-in-the-dark* pigment is trapped inside a real light bulb.  The light bulb is then encased in a solid block of acrylic resin.  The mysterious optical effect is caused by light diffracting in the tiny space between the light bulb and the resin; during the production process, the resin shrinks slightly and a space is created. The surface of the Glow Brick is polished to give a jewel-like effect.The Glow Brick comes to life in the dark, as the pigment inside the light bulb emits a subtle, tranquil glow.

*The technical term for glow-in-the-dark is ‘photoluminescence’ – the process by which energy is absorbed by a substance and released relatively slowly in the form of light.