Lava lamp
A lava lamp is a decorative lamp, invented in 1963 by British entrepreneur Edward Craven Walker, who made the lighting company Mathmos. The lamp usually takes 2 to 6 hours to heat up, but this also depends on the light bulb which is heating the wax. The lamps are designed in a variety of styles and colours, for example, a mixture of blue and red. The wax inside usually reflects the colours.