Faces of rudraksha have different powers as per purans. different faces of rudraksha said to have different secret powers.
classes of rudraksha can be found from the holy books which classify as 14 types. Also there are classification based on barnas.
Sanctity of Rudraksha is described in many holy books like padma puran, devi bhagabat and shiva purana etc.
Rudraksha has stories explaining origin of rudraksha. Origin always dates back to Lord Shiva.
Mantra for rudraksha are used for energizing the rudraksha beads before wearing them.
Caution rudraksha wearing is needed. There should be some cases where we do not wear rudraksha.