{
  "type": "minecraft:jigsaw",
  "biomes": "#minecraft:has_structure/mineshaft",
  "step": "underground_decoration",
  "spawn_overrides": {},
  "terrain_adaptation": "beard_thin", 
  "start_pool": "hopo:portal_deepslate",
  "size": 1,  
  "start_height": {
    "absolute": -54
  },
  "max_distance_from_center": 100,
  "use_expansion_hack": false
}