CLAY BALL

Nobody buys clay ball off a villager, only the other way around. The Mason takes it in at novice for 10 clay balls per 1 emerald, and that rate beats everything else his stonecutter buys off a player, stone and nether quartz included.

It comes out of a clay block found in the world rather than a furnace or a crafting grid, and no recipe in the game turns anything else into it. No tool requirement gets in the way either, an ordinary shovel breaks a clay block just as well as an enchanted one, which is part of why the Mason prices it as cheaply to buy as he does.

The recipe runs the other way too: a crafting grid takes 4 clay balls and packs them back into 1 clay block, so a stray handful never has to sit around useless if building material is what is actually needed.

Hand 10 clay balls to a Mason at Novice, his opening tier, and he pays 1 emerald back for it. The rate is fixed in the trade file, not rolled inside a range, so a second Mason quotes exactly the same.

The best rate any villager offers is an emerald per 10 clay balls, from the Mason, and nothing else on the list pays out faster. No villager sells clay ball back, so it is emeralds out and nothing in.

One slot at the Mason takes 10 clay balls a trade, 16 trades, 16 emeralds. 8 of the 72 villagers that pay emeralds, emptied out:

16 acacia boats against 480 flint for the same 16 emeralds, 30 times the carrying, and the shortest wait is the Shepherd at 10 real minutes of shelf, gathering not counted. Clay Ball itself pays 10 an emerald, so 31 of the 72 ask less and 36 ask more.

This is the one row every Mason opens with. A villager claims a stonecutter and this offer is already sitting on his sheet, no earlier trades or banked experience required, unlike almost everything further down his list.

The slot still takes 10 clay balls at a time, 16 times before it locks, and refills on the same restock schedule as everything else he sells, up to twice a Minecraft day. Being the cheapest offer on his sheet does not make it refill any faster.

16 sales close the slot, and the wait after that runs 2 real minutes flat regardless of how quickly the trades themselves are clicked through. Two of those refills fit inside one Minecraft day, itself 20 real minutes long.

Worked that hard, one Mason clears 320 clay balls for 32 emeralds across a single day, the most reliable of his raw-material rows simply because it needs the least digging to keep supplied.

One trip, one restock: the Mason takes 160 clay balls across 16 trades before the slot locks, paying out 16 emeralds total, the best emerald-per-item return he offers on anything raw.

Where they go back: that Mason also sells bricks, his cheapest offer going the other direction, made from the very clay ball he just bought off you.

Also on the Mason's list: stone, chiseled stone bricks, granite, andesite, diorite and polished andesite.

Clay sits in patches under shallow water in rivers and lakes, and breaking a block gives four balls. It needs no tool and no light, so a river bank is the easiest bulk material in the early game.

Smelted it becomes brick, and four balls put back together make a clay block that can be smelted into terracotta instead. Those two paths are the whole reason a Mason wants the raw balls: he sells the far end of both chains.

Dripstone under a block of mud drains it into clay, slowly and for free. That is the only way to make clay rather than find it, and it turns a mangrove swamp into a brick factory.

Mud itself is dirt with a water bottle poured on it, so the whole chain starts from blocks every world has.

Fired into bricks, clay becomes the one building material that is neither stone nor wood, which is most of the reason people bother with the fuel it takes.

A Clay block breaks into 4 Clay Balls, and the Mason takes 10 per emerald, so 3 blocks cover one trade. Clay is renewable too: mud set over pointed dripstone dries into Clay, which How to Make a Mud and Clay Farm in Minecraft (Renewable) turns into a farm.