• Lava lamps are the most recognizable item of lighting in the world, and every single one of the official lamps is made by Mathmos at their factory in the UK.
  • At their peak popularity in the late 90s, Mathmos was selling 800,000 lamps per year.
  • The formula for the ‘lava’ remains a close-guarded secret, and only a few people in the company actually know the ingredients.

Following is a transcript of the video.

Lava lamps might be the most cult item of lighting in the world. Since their invention in 1963, millions of the lamps have been sold across the globe.

And while their popularity has gone through ups and downs, their instantly recognizable style isn’t going anywhere.

But what actually goes into creating these iconic lamps?

This simple yet hypnotic lamp came from pretty humble origins.

Inventor Edward Craven Walker came up with the idea after spotting a handmade egg timer that used heated wax in a cocktail shaker.

After months of testing his ideas and adapting this concept into a colourful lamp, Walker came up with his final design: as it was called at the time, the Astro lamp.

The idea was patented, and Walker started the company Mathmos.

Mathmos has now been creating lamps for over 50 years, and while it's introduced new designs, the original remains its top seller.

So, how is it made?

The process starts with custom glass bottles. Glass is blown into the shape required for each lamp.

Molten blobs of glass are dropped into a mold. A machine blows air into the top of the bottle to shape it, and the newly shaped bottles are then released and cooled.

While this is all done mechanically, everything is checked over by hand. The bottles are inspected, and any that don't make the cut are discarded.

Quality control is crucial, as each bottle needs to fit perfectly into its housing and the glass needs to withstand constant heating and cooling.

The next part of the process is metal spinning, a process that takes a thin sheet of steel and bends it around a spinning tool to create the right shape.

Each base and cap is hand spun from steel, and then the resulting pieces are polished.

Once these two components are finished, the lamp is ready to be filled. The liquid is added along with a metal spring that helps distribute heat.

The exact formula of the fluid is a well-guarded secret. But there's one key to it: density.

There are two main components in a lava lamp: a colored wax (on screen: the lava) and the colored solution that it sits in.

As the lamp heats up, the density of the wax changes and it begins to float in the liquid. When it hits the top, it cools and falls back down. Getting the density of these two ingredients just right, though, is where the secret knowledge comes in.

Once the two liquids are mixed, the bottle is submerged in hot water. This water bath cleanly separates out the liquids and stops any wax that would be stuck to the side of the bottle. Lids are glued on and the bottles are ready to go.

Mathmos has sold millions of its lamps over the years, and the design is so true to the original that you could still buy the spare parts for a lamp made in 1965. And at its peak popularity in the '90s, it was selling over 800,000 per year.