MineralVein

The plugin which manages the ore spawn is called MineralVein.

https://dev.bukkit.org/projects/mineral-veins

This is a random noise generator. The way the server is currently configured, ores are rare but when you find one, there are sure to be others clustered nearby.

The current settings are as follows:

default:
- block: GOLD_ORE
  seed: ********
  density: 0.3
  thickness: 6
  densityBonus: -0.4
  heightAvg: 20
  heightVar: 20
  heightRel: false
  heightLength: 80
  densLength: 80
  exclusive: false
  mode: replace
- block: IRON_ORE
  seed: ********
  density: 0.35
  thickness: 10
  densityBonus: -0.4
  heightAvg: 32
  heightVar: 16
  heightLength: 48
  densLength: 64
  exclusive: false
- block: REDSTONE_ORE
  seed: ********
  density: 0.5
  thickness: 3
  densityBonus: -0.5
  heightAvg: 10
  heightVar: 10
  heightLength: 10
  densLength: 30
  exclusive: false
- block: DIAMOND_ORE
  seed: ********
  density: 0.25
  thickness: 12
  densityBonus: -0.4
  heightAvg: 14
  heightVar: 6
  heightLength: 10
  densLength: 64
  exclusive: false
- block: LAPIS_ORE
  seed: ********
  density: 0.4
  thickness: 4
  densityBonus: -0.6
  heightAvg: 10
  heightVar: 10
  heightLength: 10
  densLength: 40
  exclusive: false
- block: COAL_ORE
  seed: ********
  density: 0.3
  thickness: 8
  densityBonus: -0.1
  heightAvg: 40
  heightVar: 40
  heightLength: 80
  densLength: 80
  exclusive: false