Mystery stones are powerful artifacts of still unknown and rather vague powers. Their powers seem to increase based on the amount mystery stones are in one area. To all knowledge, there are only 21 mystery stones in this world. They are said to be the crystallized tears of an ancient Goddess of Truth.

It is said each one has a unique gift that must be unlocked. They appear as small, luminous, round stones. Smooth on all sides, with each stone possessing a different color. Each tear grants an extra d6 when rolling for ability checks. 

The Ruby Tear is heavily tied to the powers of Nature, Luck, and Possibilities. One who is attuned to the Ruby Tear possesses all of the abilities of the Lucky Feat.

You have inexplicable luck that seems to kick in at just the right moment.
You have 3 luck points. Whenever you make an attack roll, an ability check, or a saving throw, you can spend one luck point to roll an additional d20. You can choose to spend one of your luck points after you roll the die, but before the outcome is determined. You choose which of the d20s is used for the attack roll, ability check, or saving throw.
You can also spend one luck point when an attack roll is made against you. Roll a d20, and then choose whether the attack uses the attacker’s roll or yours.
If more than one creature spends a luck point to influence the outcome of a roll, the points cancel each other out; no additional dice are rolled.
You regain your expended luck points when you finish a long rest.

Notes: Bonus: Ability Checks, When used in tandem with other mystery stones, they allow one to use powerful bond magic by expending energy built up over time via positive interactions with other Mystery Stone users. , requires attunement by a requires attunement by a wondrous item, artifact (requires attunement by a a mystery stone will attune itself to one person, while that person lives the stone cannot be unattuned or separated from it's user. the stone chooses the user, not the other way around., Jewelry