MCMinecraft Assets Explorer

{
  "type": "minecraft:delta_feature",
  "config": {
    "contents": {
      "Name": "minecraft:lava",
      "Properties": {
        "level": "0"
      }
    },
    "rim": {
      "Name": "minecraft:magma_block"
    },
    "rim_size": {
      "type": "minecraft:uniform",
      "max_inclusive": 2,
      "min_inclusive": 0
    },
    "size": {
      "type": "minecraft:uniform",
      "max_inclusive": 7,
      "min_inclusive": 3
    }
  }
}