Rudraksha

Rudraksha, also rudraksh, Sanskrit: rudrākṣa (Sanskrit: रूद्राक्ष)("Rudra's [Shiva's] Teardrops"), is a seed traditionally used for prayer beads in Hinduism. The seed is produced by several species of large evergreen broad-leaved tree in the genus Elaeocarpus, with Elaeocarpus ganitrus being the principal species. Rudrakshas are primarily used in India as beads for organic jewellery and mala and are valued similar to semi-precious stones. As such, they are also the source of superstitious claims similar to beliefs related to magnetic or crystal bracelets, faith healing and other medical pseudoscience.

Usually the beads of Rudraksha are strung together as a mālā. Traditionally, it is believed that the number of beads used should be 108 plus one. The extra bead is the "meru", bindu or "guru bead". If the mālā lacks a bindu, the energy is said to become cyclical and wearers who are sensitive may become dizzy.

When the beads are strung, it is advisable to do so with either a silk or a cotton thread. It is then advised to change the thread every six months to prevent it from snapping and the 109 beads from scattering. The Rudraksha mālā may also be strung with either copper, silver or gold, typically by a jeweler. A common issue with mālās wired with such metals is the mālā being tied too tightly. This may result in the insides of the Rudraksha seeds cracking and crumbling from excessive pressure. Thus, it is necessary to ensure that the mālā is tied loosely.

The mālā can be worn all the time, including when showering. Wearers may believe that it is beneficial to allow bath water to flow over the beads on on the body when bathing in cold water without chemical soaps. Wearing the mālā while in contact with chemical soaps and warm water is best avoided, however, as it can result in the Rudrakshas becoming brittle and eventually cracking.

...
Wikipedia