What is the goop inside a lava lamp?

A classic lava lamp contains a standard incandescent or halogen lamp which heats a tall (often tapered) glass bottle. A formula from a 1968 US patent consisted of water and a transparent, translucent, or opaque mix of mineral oil, paraffin wax, and carbon tetrachloride. The clear water or mineral oil can optionally be coloured with translucent dyes.