The needlelike iron deposits in this spherical quartz crystal pulse with arcane energy.

A crystal of arcane steel is designed for those who can blend magical and martial arts into a single strike. It functions only when attached to a melee weapon.
This crystal grants a +1 insight bonus on your attack roll and weapon damage roll when delivering a spell or spell-like ability through a melee attack with the weapon, and it also increases the save DC of the spell or spell-like ability by 1.

Prerequisites: Craft Magic Arms and Armor, magic weapon.
Cost to Create: 3,000 gp, 240 XP, 6 days.