A new 12-sided British pound coin is entering circulation amid concern that the round pound was too easy to counterfeit. The new coin introduced Tuesday is intended to be the most secure in the world, featuring a hologram that changes from the pound symbol to the numeral one. It also has micro-lettering and milled edges. It is slightly larger in diameter, but lighter than the round pound. And despite its many sides, the Royal Mint says the new coin will roll and has been tested for the last three years to make sure it will work in vending machines. The old coin and the new coin will co-exist together for a period of around six months. It's the first new pound coin to be introduced in 30 years.