Size for liability of a bone is size to make a spoon. R Yehuda, who is consistently more stringent with the shiurim in our perek, says enough to make teeth for a lock.

Teeth of a lock themselves don’t accept tumah, but attached to the lock, they do accept tumah. Lock for a gate though does not accept tumah, bc anything attached to the ground does not accept tumah.

Size of glass is enough to cut two excess pieces of thread from the warp/or(identical alternative) scrape the head of a weavers pick to separate the threads.

Size for rock and pebble is enough to scare away a bird. R elazar says weight of 10 zuz that would scare away an animal.

Usually stones are muktzeh, but the rabbis allowed one to move rocks in order to wipe after the bathroom on Shabbos. There’s a dispute how many stones may be moved. Either 3 stones- one size of olive, but, and egg, or a full handful or stones. Alternatively, 3 stones of either egg size of nut size.

One can move around a pebble by the rectum on Shabbos to help go to the bathroom as long as it’s done in unusual manner.

A rock used for crushing spices is not allowed for wiping on Shabbos (severe form of muktzeh) unless it had been used for wiping and is still repulsive. It is generally inadvisbake to reuse a rock for wiping as it leads to hemorrhoids, but it’s ok either if it wasn’t used on same side, if it’s already dried, or if it’s the same person.

The rabbis are lenient bc of כבוד הבריאות to move rocks for wiping even if it involves a lot of טירחא. They are not lenient to use muktzeh wood as toothpick for food stuck in teeth bc a person should have prepared that by the table before Shabbos

If moss is growing on a rock, it is תולש to remove the grass on Shabbos bc the grass is growing there. However, it is permitted to wipe with it bc even if the grass ends up coming off it’s a דבר שאינו מתכון.

One shouldn’t defecate in freshly plowed field on Shabbos bc they may discard the rock in furrow which would level the ground and that will be preparing for planting and choresh.

Perforated flowerpot on the ground is forbidden to move further from the ground. (Rabbincally bc it distances it from the place of growth) the rabbis were only lenient with rock with moss to wipe bc its a need to wipe. It is also forbidden rabbincislly to take the flowerpot off a peg and put it on the ground bc it’s like planting.

Wiping with pottery is bad for witchcraft reasons. Even on Shabbos, when would say pottery is preferred over a rock bc it’s not muktzeh, we still say not to use pottery. There’s no issue that the sharp pottery may remove hair bc it would be דבר שאינו מתכון.