Grow-your-own underwater crystal “garden”

One of those things an overtime-weary lab researcher possibly stumbled across by accident in some multi-national petro-chemical conglomerate, we reckon (see also Silly Putty and Slime). The basic premise rested on the implicit (and flawed) expectation that any child would be interested in watching small multicoloured stalagmites form as if by “magic” over a period of hours or, indeed, days inside a large liquid-filled glass bowl (or, more realistically in the Cream era child’s household, a Nescafe jar). As if that in itself were somehow edifying or educational.

At best, there was something intriguing in the packaging, which required that the “rocks” be kept separate from the powdered “solution” with which they would react once submerged (sodium silicate, if you’re interested, science fans; it stains clothes like a bastard), and which hinted at potentially explosive results should they ever come into contact whilst dry.

At worst, there was the implicit (and thwarted) expectation that the crystals would somehow form a sprawling yet microscopic metropolis in the fashion of Superman’s ice-dome city hideaway from the Alexander Salkind films. But for Sea Monkeys, you see?

Later versions tried to spice up the landscape with additional plastic models, including Orca Killer Whale and the Titanic. No, really.