GRAVEL

Gravel is one of the few things a villager will take that he will not pay for. The Fletcher wants 10 of it and an emerald on top, and what comes back is 10 flint. No emerald ever travels the other way, so this is not a sale at all: it is a machine that turns a common block into an uncommon one, and you pay the fee.

That fee is worth thinking about, because the alternative is a shovel. Broken by hand, gravel drops flint about one time in ten and stays gravel the other nine, so a stack of 64 leaves you with a handful of flint and a lot of walking. The Fletcher does not roll for it. Ten in, ten out, every time.

One trader, one offer, and it is the first tier he has. A Fletcher at novice takes 10 gravel and 1 emerald, and hands over 10 flint. He will do it 12 times before the offer greys out and he has to restock.

There is no second villager to compare against and no better tier to unlock. If you want flint from a villager, this is the price, and the only lever you have is how many Fletchers you keep.

You do not get gravel from him, you give it. That flips the usual problem: instead of hunting a villager who happens to stock what you want, you need enough raw material lying around to be worth the trip. 10 gravel per use and 12 uses means a full round of this offer eats 120 blocks and 12 emeralds.

Gravel is heavy in the sense that matters here: it falls. A riverbed or a beach gives you a flat sheet of it that you can shovel out in one pass, while an underground pocket will drop on your head the moment you dig the block underneath. Bring a shovel you do not mind wearing out, because a pickaxe is slower on it and an empty hand is slower still.

Do the arithmetic before you carry anything home. Ten gravel broken by hand averages one flint. The same ten across this counter is 10, and the difference is one emerald. Unless emeralds are the scarce thing in your world, the villager wins by a distance.

The exception is a Fortune III shovel, which turns every gravel block into flint on its own and asks for no emerald at all. If you have one, the Fletcher is only worth visiting for the stack you already broke with the wrong tool.

And keep the flint moving. It is the arrow ingredient, the flint and steel ingredient, and the thing the same Fletcher wants back from you at a later tier, so a pile of it in a chest is a pile of emeralds you have not collected yet.

Gravel obeys gravity, which makes it the most dangerous harmless block in the game. Dig upwards under a gravel pocket and the column drops on your head; the standard fix is a torch placed under it, which breaks the whole stack into items.

Broken by hand it sometimes gives flint instead of gravel, and Fortune shifts that towards flint until every block gives one. Silk Touch does the opposite and guarantees the gravel back.

Flint is the half that matters: arrows, flint and steel, and the trade a fletcher runs on. Gravel itself is mostly a path block and a way to get to the flint.