"But we mine trimonite. Hardest substance known to man. It's fifteen times harder than diamond, and extremely rare. We have little more than three tons of it on board."
Garcia to Ripley

Trimonite was the hardest material known to humans. It was 15 times harder than diamond and extremely rare.[1] LV-178 contained trimonite.



  1. Tim Lebbon. Alien: Out of the Shadows, p. 51 (2014), Titan Books.