An earring that is made

like a pot below (this earring is comprised of two segments below its hook that goes through the earlobe; the lowest segment is shaped like a pot in that it is round, wide and hollow)

and like a lentil above (the middle segment is a solid globe shaped like a lentil and made of gold or silver),

and [these two segments] came apart,

the pot[-shaped segment] is tamei

because [it is] a utensil with a receptacle,

and the lentil[-shaped segment] is tamei by itself (as it can still be used as jewelry; some say it is because it has its own name),

the hook (that goes through the earlobe) is tahor (either because it is not worn alone, or because it does not have its own name).

[An earring] that was made like a cluster [of grapes]

and [all of its beads, which formed the 'grapes'] came apart [from the hook]

is tahor (the hook for the aforementioned reason, and the beads because alone they are not used as jewelry and/or because they do not have their own name).

פרק יב משנה א

The ring of a man

is tamei.

The (decorative) ring of an animal

or of utensils

and all other rings (that are not made to serve a person, but rather to serve or decorate an animal or utensil)

are tahor.

A (metal) beam for arrows (this is either a target or a quiver)

is tamei (it is considered a utensil that serves the archer, and not the arrows)

and a [metal  beam] of prisoners (this refers to stocks used to immobilize prisoners' legs)

is tahor (because it is made to be attached to the ground).

A collar (of metal, used with a chain to restrain a prisoner) is tamei.

A chain (used to hobble a horse)

that has a clasp (which gives it additional significance)

is tamei;

one that was made for tying (and therefore was made for mere adornment)

is tahor.

The chain of grain wholesalers (one end of this chain would be anchored in place, and the other was attached to a container used to measure quantities of grain)

is tamei (as it was meant to be a permanent part of the measuring container, which is a utensil susceptible to tumah),

[the chain] of householders (which, when attached to measuring containers, was merely decorative) is tahor.

Rabbi Yosi says,

When [is this the rule for a householder's chain]?

So long as it is one link,

but if there are two

or if a chilazon (i.e. a metal piece resembling this creature) was attached to its end,

it is tamei.