GokuGavsObsidianEventHandler

package com.myfirst.myfirstmod.eventhandler;

import java.util.Random;

import com.myfirst.myfirstmod.init.MyFirstItems;

import net.minecraft.block.BlockObsidian;
import net.minecraft.item.ItemStack;
import net.minecraftforge.event.world.BlockEvent;
import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;


public class GokuGavsObsidianEventHandler {
	
	@SubscribeEvent
	 public void onDrops(BlockEvent.HarvestDropsEvent event, Random random) {
	 
	 if (event.state instanceof BlockObsidian){
	 event.drops.add(new ItemStack(MyFirstItems.obsidianrubble_item, 3 + random.nextInt(6)));
	 }
	}
}

MyBlocks

package com.myfirst.myfirstmod.init;

import com.myfirst.myfirstmod.Reference;
import com.myfirst.myfirstmod.eventhandler.GokuGavsObsidianEventHandler;

import net.minecraft.block.Block;
import net.minecraft.client.Minecraft;
import net.minecraft.client.resources.model.ModelResourceLocation;
import net.minecraft.item.Item;
import net.minecraftforge.common.MinecraftForge;
import net.minecraftforge.fml.common.FMLCommonHandler;

public class MyBlocks {
	
	
	public static void init(){
		MinecraftForge.EVENT_BUS.register(new GokuGavsObsidianEventHandler());
		
	}
	public static void register(){
		
	}
	
	public static void registerRenders(){
	}
	
	public static void registerRender(Block block){
		Item item = Item.getItemFromBlock(block);
		Minecraft.getMinecraft().getRenderItem().getItemModelMesher().register(item, 0, new ModelResourceLocation(Reference.MOD_ID + ":" + item.getUnlocalizedName().substring(5), "inventory"));
	}

}