Ore (feature)

An ore  is a feature consisting of a natural deposit of ores or other blocks in the ground.

Generation
The ore feature has two types: ore blobs and scatter ores.

A ore blob is an ellipsoidal cluster of blocks. In the overworld, underground deposits of dirt and gravel are generated in this form, followed by the more precious ores, like coal, copper, iron, gold, redstone, diamond, emerald (in mountains biomes) and lapis lazuli. They can form only in stone, deepslate, andesite, diorite, granite and tuff (also in their polished variants $$, replacing parts of structures). Two or more ores can form next to each other and appear as an ore made of more than one material.

Each ore blob has a spawn size. The maximum number of generated blocks in a blob each spawn size corresponds to is shown in the table below :

A scatter ore is a slightly dispersed cluster of blocks. Currently only ancient debris is generated in this form. Scatter ores also have a spawn size value. The maximum number of generated blocks in a scatter ore is just the spawn size.

There was also a deprecated ore type, which generates only one block in each generation attempt. It was used by emerald ore before 1.18.

ID