This fine necklace has 3 Aboleth eyes set in it as if they were precious gemstones.  1d3 of the eyes are a deep blue, the others are all a dull grey.

If there is a deep blue eye in the necklace, as an action, you may use the necklace to attempt to charm a creature.  That creature must succeed on a DC 14 Wisdom saving throw or be charmed by you.  When you use this action, roll a d20.  On a 20 the eyes of the necklace retain their current color and magical ability, on any other number one of the blue eyes fades to dull grey and becomes magically inert. 

Once per day, the charmed creature can repeat the saving throw if they are more than a mile from the necklace.  Otherwise the charm lasts until the wearer dies, or is on a different plane than the charmed creature.