Rice pullers are made of copper alloys or iridium element. This type of metals has a natural electric power or magnetic power making them highly valuable.
Pulling rice can be accomplished by attaching a copper iridium coin to a 53,000 volt power supply. This will pull a grain of rice almost 1 cm under good conditions. Puffa puffa rice works best.
This also works with US nickels and rusty old washers as well. Properties of rice pulling are commonly found in copper and iridium made items like coins, vessels, tumblers, and jewelry.