Granule

Granule is a generic term used for a small particle or grain.  The generic term is used in a lot of contexts.

 Granule (solar physics), visible structures in the photosphere of the Sun arising from activity in the Sun's convective zone
 Granule (cell biology), any of several submicroscopic structures, some with explicable origins, others noted only as cell type-specific features of unknown function
 "Azurophil granule", a structure characteristic of the azurophil eukaryotic cell type
 "Chromaffin granule", a structure characteristic of the chromophil eukaryotic cell type
 Martian spherules, spherical granules of material found on the surface of the planet Mars
 A specified particle size of 2–4 millimetres (-1– -2 on the φ scale)