Mox Diamond

If Mox Diamond would enter, 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.

{t}: Add one mana of any color to your mana pool.

You can use them as pools of concentrated magical energy, or for attack and defense. For me, yes, they
are also of use as materials for research and catalysts for ritual spells.