Orb of Shadow

Mystery users prize orbs of shadow as wizards do pearls of power. An orb of shadow appears to be a black pearl of average size and unusual luster. Once per day, you can speak a command word as a standard action to activate an orb. You must have the orb in your hand; drawing it out is a move action.
Like a pearl of power, this item allows a single extra use of a mystery, regardless of whether that mystery functions as a spell, spell-like ability, or supernatural ability. The mystery must be of a particular level, depending on the orb. Different orbs exist for recalling one mystery per day of each level from 1st through 9th and for the recall of two mysteries per day (each of a different level, 6th or lower).
Strong transmutation; CL 17th. Craft Wondrous Item; creator must be able to cast mysteries of the mystery level to be recalled; 500 gp, 40 XP, 1 day (1st) 2,000 gp, 160 XP, 4 days (2nd); 4,500 gp, 360 XP, 9 days (3rd); 8,000 gp, 640 XP, 16 days (4th); 12,500 gp, 1,000 XP, 25 days (5th); 18,000 gp, 1,440 XP, 36 days (6th); 24,500 gp 1,960 XP, 49 days (7th); 32,000 gp, 2,560 XP, 64 days (8th); 40,500 gp, 3,240 XP, 81 days (9th); or 35,000 gp, 2,800 XP, 70 days (two mysteries).
Variants: Some mystery users prefer to set an orb of shadow into a ring. In this case. you need never draw out the orb, but it occupies space on your body as a ring. Weight: - ; Price:1,000 gp (1st), 4,000 gp (2nd), 9,000 gp (3rd), 16,000 gp (4th), 25,000 gp (5th), 36,000 gp (6th), 49,000 gp (7th), 64,000 gp (8th), 81,000 gp (9th), or 70,000 gp (two mysteries).
Source: Tome of Magic