JEI Ores Mod FAQ

Open JEI's item list, find an ore block, and press U (usage key) to view its spawn information. The screen will show the minimum and maximum Y-levels where that ore generates.

Ore spawn heights vary by dimension and can be affected by other mods or custom world generation settings. Check that you're looking at information for the correct dimension, and verify your modpack hasn't changed ore generation rules.

Yes, but the mod must be installed on both your client and the server. If it's only on one side, the mod disables itself automatically to prevent desyncs.

Yes, the mod automatically detects and displays spawn data for custom ores from other mods without requiring any extra configuration.

Cluster size tells you roughly how many ore blocks are grouped together in a single vein, helping you decide how much mining effort to invest in one location.

Open the ore's spawn information in JEI and look for a biome restriction section. If it's listed, only those biomes will contain that ore.

Make sure you're pressing the usage key (U by default) on the ore block itself, not just hovering. If information still doesn't appear, verify the mod is installed correctly and check for mod conflicts.

JEI Ores has minimal performance impact since it only displays pre-calculated spawn data when you look it up. It doesn't change how the world generates.

Yes in single-player without restrictions. For multiplayer, install it on both client and server; if only installed on one side, it will disable itself.

Check the spawn height ranges for each ore you want using JEI, then find the Y-level range where they overlap. This lets you mine efficiently in one vertical tunnel.