{
  "criteria": {
    "trigger": {
      "trigger": "minecraft:using_item",
      "conditions": {
        "item": {
          "items": "minecraft:amethyst_shard",
          "components": {
            "minecraft:custom_data": "{gravity_crystal:1b}"
          }
        }
      }
    }
  },
  "rewards": {
    "function": "kiwi:enchantment_function/gravitron_shadow"
  }
}