2,908. A Dozen Forms of Impurity
Hilchos Nezirus 7:2
A nazir must shave because of contamination from the following types of corpse impurity: a stillbirth, even if the sinews connecting the limbs haven’t formed; an olive-sized piece of flesh from a corpse; an olive-sized volume of decomposition; bones from a corpse that comprise the majority of its bones even if their volume is smaller than a quarter-kav; bones that comprise the majority of the skeleton even though their volume is smaller than a quarter-kav; a half-kav of bones even if they don’t comprise the majority of the number of bones or of the skeleton – all the bones must come from a single corpse and not from two; the spine of a single corpse; the skull of a single corpse; a limb from a single corpse; a limb removed from a living person that has flesh that would grow back in a living person; half a log of blood from one corpse; a handful of rot from a corpse. “Neztel” (translated above as “decomposition”) refers to the flesh of a corpse that has decomposed to the state of a rancid liquid.
Hilchos Nezirus 7:3
The rot of a corpse only transmits ritual impurity if the body was buried completely intact, naked in a marble casket. If a limb was missing or if the body was buried clothed, or in a casket of wood or metal, then the concept of rot doesn’t apply. The idea of rot only applies to a corpse alone. It doesn’t include a person who was killed because such a corpse is missing blood.