spicule

A sharp, needle-like piece.

A tiny glass flake formed during the manufacture of glass vials.

Any of many needle-like crystalline structures that provide skeletal support in marine invertebrates like sponges.

Tear it up, and put a fragment under the microscope, and, wonder of wonders! see the maze of geometric forms exhibited in the bones of the creature; for who can help regarding the spicules as bones, even though a sponge be invertebrate?

A needle-like mating structure found only in male nematodes.

A jet of matter ejected from the photosphere of the sun.