Updated to 1.20
Clay blocks and Diamond Ores are linked. You can easily find Diamonds following a simple step by step process, starting from a Clay patch. Today we are here to see this Clay-Diamond trick in details. Let’s start!

Where to find Clay patches
This method for finding Diamonds doesn’t work with every block of Clay that you can find. You will need to start from Clay patches in Swamp biomes.

In Swamps you will find those circular (“circular” considering Minecraft’s standards) Clay patches underwater. This method works also for Clay patches in River biomes, but in Swamps there is a higher chance for it to work.
If you can’t find any Swamp, you can try to use the /locate biome command. To use commands you will need to have cheats allowed in your Minecraft world. If cheats are not allowed in your world, there is a workaround. You can check here how to still use cheats in that Minecraft world.
To use locate biome you just need to open the commands and type:
/locate biome minecraft:swamp
And you’ll see a message appearing with the coordinates ot the closest Swamp.

Now what you have to do to get there is just closing the gap between your coordinates (that you can see by pressing F3) and the coordinates of the biome that you want to go to.

Where to dig for Diamonds
First and foremost, press F3+G to see the chunk’s borders. This is very important. The chunk’s borders will look like this.

Go to the center block of a Clay patch. From there, go to the 6th block North.

To know where the North is, you can press F3. The blue arrow at the center will point North (also known as the positive Z-axis).

If the 6th block North from the center of the Clay patch is in another chunk, like in the following screenshot:

then you have to continue counting on the other side of the same chunk:

You can start digging down from that block.
Always be careful when digging straight down, you could easily die from fall damage or end up in a Lava pool. That’s why you may want to dig following a vertical stairs pattern.

All you have to do is dig down until you find Diamond Ores.

When the Clay trick doesn’t work
- This system doesn’t have a 100% chances of success (more like 80%), so you will not always find Diamonds this way
- It also does not work in all seeds. If you try it on 5/6 or more Clay patches and you don’t find any Diamond, chances are that it is not going to work in all the Minecraft world you are playing
- It doesn’t work if you are playing the Java 1.13 patch or older
- This method doesn’t seem to work in Minecraft Bedrock edition
Credits to Matthew Bolan who discovered and covered the correlation between Clay and Diamonds.
Conclusions
The Clay-Diamond trick is a great way to find plenty of Diamonds without having to strip mine, something that players usually don’t love (to say the least). You need to find a Clay patch in a Swamp, then dig down starting from the 6th block North from the center of the clay patch. If the 6th block North from the center of the Clay patch is in another chunk, then you have to continue counting on the other side of the same chunk. Thank you very much for reading the article this far and I hope I’ll see you again around here. See you and take care!