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This is a list of notable fictional materials from the science fiction universe of Star Trek. Like other aspects of stories in the franchise, some were recurring plot elements from one episode or series to another.

The fictional metals duranium and tritanium were referred to in many episodes as extremely hard alloys used in starship hulls and hand-held tools. The planet-killer in "The Doomsday Machine" had a hull made of solid neutronium, which is capable of withstanding a starship's phasers. Neutronium is considered to be virtually indestructible; the only known way of stopping the planet-killer is to destroy it from the inside via the explosion of a starship's warp core.

Star Trek technical manuals indicate that transparent aluminum is used in various fittings in starships, including exterior ship portals and windows. It was notably mentioned in the 1986 film Star Trek IV: The Voyage Home. Ultra-strong transparent panels were needed to construct water tanks within their ship's cargo bay for containing two humpback whales and tons of water. However, the Enterprise crew, without money appropriate to the period, found it necessary to barter for the required materials. Chief Engineer Montgomery Scott exchanges the chemical formula for transparent aluminum for the needed material. When Dr. Leonard McCoy informs Scott that giving Dr. Nichols (Alex Henteloff) the formula is altering the future, the engineer responds, "Why? How do we know he didn't invent the thing?" (In the novelization of the film, Scott is aware that Dr. Marcus "Mark" Nichols, the Plexicorp scientist with whom he and McCoy deal, was its "inventor," and concludes that his giving of the formula is a predestination paradox/bootstrap paradox.) The substance is described as being as transparent as glass while possessing the strength and density of high-grade aluminum. It was also mentioned in Star Trek: The Next Generation episode "In Theory".

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