The moss blocks in Minecraft are a helpful item that you can use to spawn Azalea Trees and Azalea leaves. There are a few ways you can obtain this block and put it in a location that’s more suitable for you. Unfortunately, for the first part of Minecraft’s Caves and Cliff update in patch 1.17, this block does not naturally generate in the world. It does show up in other locations, though.
Normally, a moss block would spawn inside lush caves. You should find these underneath Azalea Trees that naturally spawn in Minecraft. However, lush caves were not added in update 1.17, and there are no naturally spawning Azalea Trees. The only way you can obtain moss blocks is by trading the Wandering Trader for them or by looting chests found in shipwrecks.
Shipwrecks can appear in most ocean biomes, but they’re pretty rare. Inside the shipwreck, you should be able to find a few chests. Depending on the size of the shipwreck, and the parts that you find, you can find one to three chests inside of it. More often than not, you’re going to encounter only one. If you’re looking for moss blocks, you want to invest in the supply chests, which are in the ship’s bow, the front section.
Alternatively, you can speak to a Wandering Trader. They will trade you two moss blocks for a single emerald. A good way to combine these two is to investigate shipwrecks first. If you don’t find a supply chest, there’s a chest for a treasure chest, and those could contain an emerald. All you have to do is find a Wandering Trader, and you’ll be able to get your moss block.
There are several items you can create using a moss block. You can turn it into moss carpet, a mossy cobblestone, or mossy stone breaks. If you give it bone meal, you can spawn Azalea leaves and then create an Azalea Tree, even though they do not naturally spawn in Minecraft yet.