Trisilicate

Fictional record. This page describes a mining commodity from a fictional setting, not a real material. Information is based on the cited canon, with adaptations and interpretation distinguished where necessary. It is kept separate from the real MineArchive corpus — see Fictional.

The mineral of the two Peladon serials of Doctor Who: a crystalline ore on which the Galactic Federation's technology rests, thought by the Doctor to exist only on Mars until it was found on Peladon, and the prize of the Federation's war with Galaxy Five.

Where it occurs

Mars, where the Third Doctor at first believed it was found exclusively, and Peladon, whose seams run under Mount Megeshra and were worked by the planet's own miners in The Monster of Peladon. The expanded universe adds Yama-10, the planet ERM 4997, Laylora where the natives found it a nuisance, and a rich untapped seam under an Osiran tomb on Peladon in the 41st century; by 3985, in one novel, Peladon's deposits were almost mined out.

How it's obtained

Dug by the Pels of the lower class in the citadel's mines, with the Federation's mining engineer Eckersley pressing the sonic lance on them to cut straight into the main seam and raise output tenfold. The miners, already working harder for the Federation than they ever had for themselves, feared the new tools after a man died at the face, and their revolt under Gebek is the serial's story.

Properties

Eckersley says the Federation's whole technology is based on it, electronic circuitry included, and the serial treats the ore as the raw material for refinement. An audio play later calls it the hardest form of salt in the galaxy.

Why it's valuable

The Federation's war with Galaxy Five turned on the trisilicate supply, and the serial's villain, Eckersley, with a rogue faction of Ice Warriors, planned to ship Peladon's ore to the enemy. The miners' rebellion against the Federation and their own rulers is the serial's picture of a strike in a company town, broadcast in 1974 between the two national coal strikes.

Uses

Federation technology generally, electronic circuitry specifically; in the expanded universe, crystals burned as ship fuel and a filament bridge between two moons.

Canon & adaptations

The Curse of Peladon has the Doctor believe the mineral is found only on Mars; The Monster of Peladon finds it on Peladon in quantity, and the expanded universe scatters it across the galaxy. The producer Barry Letts took the name from the ingredients on a tube of Boots toothpaste.

Recorded claims

Each claim is marked with its basis — explicit canon, MineArchive inference, adaptation only, or fandom interpretation — and attached to the source(s) below. Where tellings disagree, both are kept.

• Eckersley tells the Doctor that the Federation's whole technology, electronic circuitry included, is based on trisilicate and that production must be stepped up for the war with Galaxy Five. (explicit canon) ¹
• The Federation pressed the sonic lance on Peladon's miners to cut direct access to the main seam and increase output tenfold, and a miner died at the face when it was first used. (explicit canon) ¹
• In The Curse of Peladon the Doctor believed trisilicate was found exclusively on Mars; The Monster of Peladon finds Peladon rich in it. (explicit canon) ^1,2,3
• Eckersley and a rogue faction of Ice Warriors planned to ship Peladon's trisilicate to Galaxy Five, and were defeated by the Doctor and the miners. (explicit canon) ^1,4
• Barry Letts took the name trisilicate from the list of ingredients on a tube of Boots toothpaste. (fandom interpretation, uncertain) ³

Fictional mines producing this

Included only where MineArchive's own research gives a reasonable evidential basis.

• The Trisilicate Mines of Peladon
  The ore the Pels dug under Mount Megeshra for the Federation.

Sources

1. (primary canon) The Monster of Peladon — camera script transcript, Doctor Who season 11 story 4 (1974) — chakoteya.net Doctor Who transcripts
2. (primary canon) The Curse of Peladon — camera script transcript, Doctor Who season 9 story 2 (1972) — chakoteya.net Doctor Who transcripts
3. (interpretation) Trisilicate — TARDIS Data Core — TARDIS Data Core (Fandom), citing the television serials, audio plays, novels and comics; read through the MediaWiki API
4. (interpretation) Peladon — TARDIS Data Core — TARDIS Data Core (Fandom); read through the MediaWiki API

Record created: 16 October 2026 · Last researched: 16 October 2026