name="Redstone Pickaxe"; id=1034; type="normal"; iconfile="customitems.png"; iconindex=37; maxuses=750; damage=4; efficiency=18; repairable="true"; harvestlevel=2; toolclass="pickaxe"; efficiencyblocks="pickaxe"; blockdestroyed = "player.damageItem(player.getCurrentSlot(), 1);"; hitmob = "player.damageItem(player.getCurrentSlot(), 2);";
This example is a pickaxe made out of redstone that can break blocks really fast, but has lower durability then diamond tools. The redstone pickaxe can't break obsidian because it isn't defined in the 'harvestblocks' attribute.
Vanilla Efficiency Attributes
A small list of the vanilla tools with their efficiency can be found on the right.
All tools of one kind like iron have the same efficiency, means that an iron shovel has the same efficiency like an iron pickaxe, the difference is defined in 'toolclass', 'efficiencyblocks' and 'harvestblocks'.