sapphire

a whisker grown of Al₂O₃
stays just as gracile as it's getting long
anisotropic growth in just one-D
but on that axis, it's ungodly strong.
Molecularly, it's a whole new class
from aggregates one might pull off the shelf
its strength per weight surpasses fiberglass
each bond aligned with load, all by itself
the homolytic bond strength's hard to beat
aluminates adhere both snug, and fast
a fancy aggregate used in concrete
resistant to an earthquake, or bomb-blast
composites tough as abalone shell
might yet survive when Earth's been made a Hell