Description

This mod is meant to make access to the main vanilla ores less cheaper and more challenging, trying to don't alter the original supplying materials.
It may work better in a Vanilla Plus scenario, not heavily modded, where the main resources are a key part of the survival.
The Vanilla coal and iron are replaced by several variants of them from real life, depending on level, biome, quantity and quality of the contained resource. Configuring the abundance of each ore, it will take more exploration and caving for the better quality supplies and some planning for the most efficient usage.

Known Issues
Due to lack of strong coding skills this mod may not perform well on servers because of lag and sync issues when extensively using machines. It should run fine though for single players. I'm sorry about it.