All the prehistoric epics of Padma Puran, Shiv Puran, Shri Mad Devi Bhagwat and Skand Puran, however refer Rudraksha only upto 14 Mukhi. Still, Rudraksha upto 21 Mukhi have been found, together with some other popular beads like Gauri Shankar (2 beads fused naturally from the tree), Ganesha (having a trunk like projection) Savar ( a Gauri Shankar having one bead with 1 Mukh), Nandi ( a bead with two horn like projection), Ved ( a bead with 4 one mukhi sawars around it ) etc. Of late a bead with 27 mukh has also been discovered.
Rudrakshas from Nepal are mostly huge in size, upto 25 mm to 30 mm in diameter and have apparent distinct lines. In contrast, Rudraksha from Indonesia are smaller in size and the lines are not so profound, but recognisable with attempts. These Indonesian beads are generally used to make Malas (stringed ornament worn round the neck) and have diameters from 12mm, reaching upto 44mm.
Most of these malas, which one usually sees, are 5 Mukhi in 4mm to 10mm diameter in size, but lesser quantities of 4,6,7 & 8 Mukhi Malas in small sizes are also made after arranging the beads. Rudrakshas come in various colours, such as white, red, brown, yellow & black. The most popularly available Rudraksha is brown in colour. After dousing it in oil and after prolonged usage, all Rudrakshas turn deep brown or even black in colour.
Rudraksha is a very powerful bead and with appropriate maintenance, it can survive for thousands of years. The bead has done good to humankind in several ways and lot of research has been exercised to find out how the Rudraksha actually functions.
Some research work indicates towards inducive power, bipolarity etc., but it is normally thought that the potential of Rudraksha cannot be evaluated with accessible instruments but can be sensed by everybody who wears it- both physically and by mental configuration.
If ornaments of Lord Shiva can be analysed, one will find that all of them represent powers like ash from the funeral pyre, tiger skin, snakes and river Ganges, moon, poison in the neck (Neel Kantha), Mala of Human Skeleton & the flower from the enrapturing Dhatura tree. All these signal towards the fact that Rudraksha must be a very powerful bead.
The basic question now lies to uncover what exact power does Rudraksha possess. After interrelating with a number of groups of people, there is solid reason to consider that Rudraksha renders beneficial results to every person who wears it. One can be healed from various illnesses or receive wanted materialistic or sacred gains. The Power or Shakti of Rudraksha is an integration of power from --
1. Providential characteristics by blessings of numerous Gods and Goddesses.
2. Physical impact on the body, which sends neuro signals to make the mind tension-free and thereby proving the functioning, which can be termed as "Self Empowerment".
Different Mukhi Rudrakshas have different impressions on humans & one can wear all kinds of Rudraksha, either individually or collectively.