Breaking with tools

I am trying to make a block that can be mined with an iron pickaxe or higher. but no matter what I've tried, it still is able to break with my fists. help pls

BlockInit: 
 

package com.CannedMan100000.cursedworldmod.init;

import com.CannedMan100000.cursedworldmod.CursedWorldMod;
import com.CannedMan100000.cursedworldmod.CursedWorldMod.CursedWorldItemGroup;

import net.minecraft.block.Block;
import net.minecraft.block.SoundType;
import net.minecraft.block.material.Material;
import net.minecraft.item.BlockItem;
import net.minecraft.item.Item;
import net.minecraftforge.common.ToolType;
import net.minecraftforge.event.RegistryEvent;
import net.minecraftforge.eventbus.api.SubscribeEvent;
import net.minecraftforge.fml.common.Mod;
import net.minecraftforge.fml.common.Mod.EventBusSubscriber.Bus;
import net.minecraftforge.registries.ObjectHolder;

@ObjectHolder(CursedWorldMod.MOD_ID)
@Mod.EventBusSubscriber(modid = CursedWorldMod.MOD_ID, bus = Bus.MOD)
public class BlockInit
{
    public static final Block heirlium_ore = null;
    public static final Block cursed_stone = null;
    public static final Block cursed_cobblestone = null;
    
    @SubscribeEvent
    public static void registerBlocks(final RegistryEvent.Register<Block> event)
    {
        event.getRegistry().register(new Block(Block.Properties.create(Material.EARTH).hardnessAndResistance(3f, 15f).sound(SoundType.STONE).harvestLevel(2).harvestTool(ToolType.PICKAXE)).setRegistryName("heirlium_ore"));
        event.getRegistry().register(new Block(Block.Properties.create(Material.EARTH).hardnessAndResistance(3f, 15f).sound(SoundType.STONE).harvestLevel(2).harvestTool(ToolType.PICKAXE)).setRegistryName("cursed_stone"));
        event.getRegistry().register(new Block(Block.Properties.create(Material.EARTH).hardnessAndResistance(3f, 15f).sound(SoundType.STONE).harvestLevel(2).harvestTool(ToolType.PICKAXE)).setRegistryName("cursed_cobblestone"));
    }
    
    @SubscribeEvent
    public static void registerBlocksItems(final RegistryEvent.Register<Item> event)
    {
        event.getRegistry().register(new BlockItem(heirlium_ore, new Item.Properties().maxStackSize(64).group(CursedWorldItemGroup.instance)).setRegistryName("heirlium_ore"));
        event.getRegistry().register(new BlockItem(cursed_stone, new Item.Properties().maxStackSize(64).group(CursedWorldItemGroup.instance)).setRegistryName("cursed_stone"));
        event.getRegistry().register(new BlockItem(cursed_cobblestone, new Item.Properties().maxStackSize(64).group(CursedWorldItemGroup.instance)).setRegistryName("cursed_cobblestone"));
    }
}

Loot table:

{
  "type": "minecraft:block",
  "pools": [
    {
      "rolls": 1,
      "entries": [
        {
          "type": "minecraft:alternatives",
          "children": [
            {
              "type": "minecraft:item",
              "conditions": [
                {
                  "condition": "minecraft:match_tool",
                  "predicate": {
                    "enchantments": [
                      {
                        "enchantment": "minecraft:silk_touch",
                        "levels": {
                          "min": 1
                        }
                      }
                    ]
                  }
                }
              ],
              "name": "cursedworld:cursed_stone"
            },
            {
              "type": "minecraft:item",
              "conditions": [
                {
                  "condition": "minecraft:survives_explosion"
                }
              ],
              "name": "cursedworld:cursed_cobblestone"
            }
          ]
        }
      ]
    }
  ]
}

This is for all but I'm just showing u the cursed stone for now. I'll implement it later.

Minecraft 1.15.2