Anvil

Anvil is a block. Unlike in vanilla Minecraft, it cannot be broken and it is unknown how some anvils usually on auction house are damaged.

Location
One can be found in the Village near the Blacksmith or in front of the Gold Mine, or crafted and placed in the Player’s island with the normal vanilla recipe.

Combining Enchanted Books
The Anvil is often used to combine low-level Enchanted Books to increase their level. It takes two of the same level to increase, so it is not possible to get a level V book from 5 level I books. Instead, it would take a total of eight level I books to create a level V book. This does not work for all levels, however, as many high-level enchantments (usually level VI or higher) are obtained from Dungeons or Experiments.

Combining Tools
Two items of the same type can be combined to add their enchantments, just like Vanilla Minecraft. However, unlike Vanilla Minecraft, it does not increase durability, because there is no durability in Skyblock. For this reason, it is not recommended to combine tools of a high rarity because it is usually much cheaper to just add more enchantments than to get a second tool of the same type.

Scam Prevention
Unlike Vanilla Minecraft, items cannot be renamed. This is to prevent people renaming cheap tools to more expensive tools that look similar and selling it on the Auction House (like renaming a wooden hoe, which is worth about 5 coins, to a Mathematical Hoe Blueprint, which can sell for over a million.