Perennial Arcane Marble

"A marble made entirely from the arcane mana of the Harbinger of Primeval Origins. The arcane marble is perfectly stable, leaking no energy, and remains utterly unaffected by all outside influences that do not originate from its creator. This marble is incredibly durable, but should it be damaged, it shall react violently and lash out with the power of pure destruction at whatever broke it. A faint amount of pure, unrecognizable energy is sealed within the marble. Through this energy, a perennial existence awaits."