Keilim 30:2-3

Keilim 30:2

A mirror is insusceptible to ritual impurity; a tray that was made into a mirror remains susceptible but if it was originally designed for use as a mirror, then it’s insusceptible. A glass ladle is susceptible to impurity if it can hold any volume at all when laid on a table. If it can’t do so, Rabbi Akiva rules it susceptible to impurity and Rabbi Yochanan ben Nuri rules it insusceptible.

Keilim 30:3

If the greater part of a cup is dented, it is insusceptible to impurity; if three dents cover the greater part of it, it is likewise insusceptible. Rabbi Shimon says the cup is only insusceptible to impurity if it lets the majority of the water spill out. If the cup was punctured and patched with lead or tar, it is insusceptible to impurity; Rabbi Yosi says it’s susceptible if patched with tin and insusceptible if patched with tar.