
Calcite Veins: Motherlode-Style Regional Ores for Chunk Mining
Replaces vanilla ore motherlodes with large, calcite-based veins for all vanilla ores, encouraging cave exploration and long-term mining projects
⬇ Download on Modrinth




About
A white cluster of calcite in the corner of an otherwise-empty noise cave hints at potentially hundreds of ores behind the wall. Scoping out the motherlode, planning routes around it, and eventually chunk-mining it all is a massive undertaking - one that can become a central focus of your playthrough.

This mod adds "calcite veins" to the game: large ore deposits where ores are separated and spread out over a wide area. Mining them involves excavating a large region over time.
Calcite veins replace vanilla iron and copper motherlodes, and also add equivalent veins for every vanilla ore type. They do not change the normal small ore blobs in any way.
The size of these veins varies greatly. Sometimes you will find a vein with only 10 ores inside, but the vein shown above contains 1609 ores. Fully mining them out can be non-trivial, so larger veins act as long-term mining hubs rather than quick resource grabs. This variance is intentional. You can get lucky and completely break the emerald economy or jump straight to an effectively endless diamond source. Or you might find basically nothing. Veins are generated by noise maps rather than being evenly distributed per chunk, so outcomes are unpredictable.
These veins do not use the air exposure reduction mechanic, which makes large noise caves one of the best ways to discover them. Exploring cave systems is now rewarded with potentially huge jackpots.
Spawning
Each different ore type has a specific height at which they generate:
- Coal - 60 to 16
- Copper - 60 to -16
- Iron - 60 to -32
- Gold - 32 to -32
- Lapis - 16 to -48
- Redstone - 16 to -32
- Diamond - -16 to -64
- Emerald - -16 to -64
In the Nether, gold nuggets and quartz generate in "blackstone" veins, which work exactly the same way. These can appear at any height, and also generate in the bedrock ceiling, allowing easier access to the nether roof (see gallery).
Datapack
This mod is mostly datapack-driven, with the Java code only editing the vanilla motherload generation to hardcode in calcite blocks. If you would like to customise the ore generation, or add new ones, see the data folder in the source code on Github.
Compatibility
This mod was originally made for a personal modpack. As a result, it overwrites the entire create() method of OreVeinSampler, which may conflict with other mods that modify vanilla motherlode generation.
This should be safe to uninstall at any time (as long as you keep universal ores installed). If you install this to an existing world, the veins will only generate in newly loaded chunks. A new world is recommended.
Requirements
- Universal Ores: adds the calcite ore blocks used by these veins
- Custom Ore Veins: the framework the datapack uses to define these veins
- Edition: Minecraft Java
- File type: .jar
- Minecraft version listed: 1.20.1
- How to install: Install the matching mod loader (Forge, Fabric or NeoForge) for your Minecraft version. → Download the .jar. → Put it in the .minecraft/mods folder and launch that loader profile.
- Where to get it: Opens on Modrinth — not every file is mirrored on our own servers.
Install steps are the general flow for this file type — How to install Minecraft Java mods & modpacks walks through it step by step.
- Ships as calciteveins-1.0.2-1.20.1.jar — drop this file into the mods folder
- Download size: 35 KB
- Download link checked 9 Sept 2026 — working
These come from our own check of the pack file, not from the source page.