Lumesium

An MCreator mod that adds in a new ore, Lumesium. It can replace veins of either Coal, Iron, or Gold. You can find up to 9 blocks of it in a vein and it is less rare than Gold but more rare than Redstone when spawning in chunks. It requires Stone tools at minimum to collect and gives 2 experience per block. 

Putting 9 Lumesium Shards in a Crafting Table will make a Lumesium Heart. Right click with it in your hand and it’ll give you an additional heart of maximum health.