User blog comment:Unownshipper/Metallurgists Wanted: Rapture's Natural Resources/@comment-75.36.142.53-20140810065007/@comment-75.36.142.53-20140810155510

Fibers made from glass, ceramics and rock (including basalt). Used as insulation and as growth medium in hydroponics.

Can be used as a strengthener for plastics and cement/concrete.