Your search for "Marble Diamond 298" revealed the following:
Marble Diamond (6ED) from Classic Sixth Edition, available at 401 Games Canada. Rarity: Uncommon Finish: Normal Artist: Jeff Miracola Card Text:Marble Diamond comes into play tapped.T: Add W to your mana pool.
Lee Sin - Centered - 151b/298 - Rare from Riftbound: Organized Play Promos, available at 401 Games Canada. Rarity: Rare Finish: Foil Artist: League Splash Team Card Text:ACCELERATEOther buffed friendly units at my battlefield have +2 Might.