Rupture Spire (DDH) from Duel Decks: Ajani vs. Nicol Bolas, available at 401 Games Canada.

• Rarity: Common
• Finish: Normal
• Artist: Jaime Jones
• Card Text:
  Rupture Spire enters the battlefield tapped.
  When Rupture Spire enters the battlefield, sacrifice it unless you pay 1.
  T: Add one mana of any color to your mana pool.