Inspired by the microscopy (I am a microscopist by trade also - electron microscopy in fact) of Professor Gary Greenberg, I made a tiny nautilus image as might appear in a grain of sand. And not wanting to perpetuate any myths by my rhyme below, I will relate his "method of sand creation" which is by the action of rocks on their way to the river.  I guess they are then polished, as it were, by the action of the tides.  So here is a stained glass ground up nautilus grain of sand pattern. 

a tiny little nautilus
is pummeled by the sea
into an itsy-bitsy grain of sand
that neither you nor "eye" can see