What is the "lava" in a lava lamp made up of?

The soothing flow of a lava lamp in motion can be hypnotizing, but have you ever wondered what exactly it is you're looking at?

Initially, lava lamp manufacturers tended to be secretive about what makes their goo so entrancing. However, it is fairly obvious to observers that there are two different substances in there that do not mix - so, what are they?

Of course we know that the “lava” in the lamp isn't real magma. Fortunately for inquiring minds, industry professionals have disclosed a few “secrets” over the years. As it turns out, in most cases the globs which float up and slowly descend, are primarily paraffin wax.

The liquid surrounding the wax is mostly water, plus a proprietary blend of chemicals that gives it a similar density to wax. Exact ingredients & amounts may vary between manufacturers, but the watery-looking base liquid is mostly water, colored dye, and chemicals that prevent the formation of fungus.

When the lamp is turned on, the colorful wax at the bottom heats up. Heat from the base of the unit causes it to expand, lose density, and float to the top. Once there, away from the heat source, it cools off and drops back down, starting the cycle over again.

Once the lamp is turned off, and heat is no longer part of the equation, the cooled wax all settles to the bottom.