In James Cameron’s Terminator 2: Judgment Day, what liquid-metal material forms the T-1000?

In James Cameron’s Terminator 2: Judgment Day, the T-1000 is formed from mimetic poly-alloy.

The material is a fictional advanced metal that allows the T-1000 to change shape, imitate people, and pass through openings. Its liquid appearance is a defining visual feature of the character, who is portrayed by Robert Patrick. Unlike the solid-metal T-800, the T-1000 is a prototype infiltrator built around a radically different design.

The phrase “mimetic poly-alloy” appears in the film’s dialogue and official terminology. “Mimetic” refers to the material’s ability to imitate forms, while “poly-alloy” indicates its fictional composite-metal nature. It is not the same as mercury, even though the flowing visual effects can resemble liquid metal.

The character’s visual effects were a major technical achievement for early-1990s cinema. Industrial Light & Magic used computer-generated imagery alongside practical effects to depict the T-1000 morphing and recovering from damage.