It is said, that whomever manages to flip the coin, there is a 50/50 chance that their wish may come true.

To activate the items magic ability, one first must clearly formulate the Wish aloud in any language.
Next, one must pick "Stars or Darkness"
Then, one must flip the coin within the hour.
Upon the coin landing on either side, if the flipper has chosen the same side that is now pointing up, his wish will be granted.
In the case that the flipper has chosen the wrong side of the coin, it is unclear, what exactly may happen.