The limpet teeth's microscopic structure is analogous to man-made short-fiber composites. Its strength depends on the direction of the force, relative to the orientation of the fibers.
For worldbuilders, this thing is a gift from Glarnak (our awesome god). Basically, an organic substitute for carbon fiber. The only real problem is the density, as its mostly made of the mineral, goethite. Graphene is reactive but reasonably stable enough for a living creature to use. So, I wanted to replace the goethite fibers with carbon nanotubes of the same length or something similarly lightweight.
Can I replace goethite whith something else in limpet teeth to decrease its density without decreasing its strength?