If Mox Diamond would enter the battlefield, you may discard a land card instead. If you do, put Mox Diamond onto the battlefield. If you don't, put it into its owner's graveyard. : Add one mana of any color to your mana pool.
Official Rulings for Mox Diamond
5/1/2008 : If you don't discard a land card, Mox Diamond never enters the battlefield. It won't trigger abilities that look for something entering the battlefield, and you won't get the opportunity to tap it for mana.
Comments on Mox Diamond
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