Aura moderate transmutation; CL 12th
Slot none; Price: 10,000 gp; Weight —.
Each stone of this type is keyed to a particular kind of weapon (heavy flail, light crossbow, short sword, and so on) and grants you proficiency with that weapon.
Cracked: The stone grants the wearer weapon familiarity with the keyed weapon (it is treated as a martial weapon for him). Price: 1,500 gp.
Flawed: This stone grants proficiency with the keyed weapon and gives the wearer a –2 penalty to Dexterity. Price: 3,000 gp.
See Inferior Ioun Stones for details on cracked and flawed variant stones.