It was an unusual blend of the supernatural chiller, and space-time claustrophobia. As the voice-over to the introduction explained:
All irregularities will be handled by the forces controlling each dimension. Transuranic, heavy elements may not be used where there is life. Medium atomic weights are available: Gold, Lead, Copper, Jet, Diamond, Radium, Sapphire, Silver and Steel. Sapphire and Steel have been assigned.
Which seems rather unfair to the transuranic elements. A fairly haphazard collection of minerals, alloys, gemstones, and chemical elements seem to have been bundled together here. Moreover, lead is nothing if not a heavy element, and radium has a somewhat tarnished reputation when it comes to its life-enhancing properties.
What is splendid about the opening sequence, however, is the way the nuclei of the chemical elements are represented as if they're also miniature gemstones, with hundreds of sparkling, colourful facets. It's a notion which modern mass spectrometers do little to promote, yet this diagram of the uranium-238 radioactive decay chain does seem to owe a little something to the idea.