Kommentar zu Kelim 14:6

כיסוי של טני של מתכת (covering of a metal basket) – of house owners, is ritually pure, according to the words of Sages who dispute on that of Rabban Gamaliel above in Chapter 12 [Mishnah 6] (of Tractate Kelim). But if he cleansed it and polished it and made from it a mirror, ר' יהודה מטהר – for he holds that a mirror is not worth to him anything.

A metal basket-cover which was turned into a mirror: Rabbi Judah rules that it is clean. And the sages rule that it is susceptible to impurity. Had it not been made into a mirror, all would agree that this metal basket-cover is pure because it is a metal object used for the purposes of a wooden object (see 12:6). As we learned, in such cases the vessel has the status of being made of wood. However, if he polishes it and makes it into its own vessel to be used as a mirror, it is susceptible, according to the sages. Rabbi Judah holds that it is still not considered a vessel and it is still pure.

וחכמים מטמאין – for a mirror is worth to him something. And the Halakha is according to the Sages.

A broken mirror, if it does not reflect the greater part of the face, is clean. If the broken mirror cannot show most of a person's face, it is no longer susceptible to impurity because it is really not usable. But if it can still reflect most of the face, it is still usable.