Excerpts from Holy Books

Siva Purana Vidyesvara Samhita Translated by Shastri 1973.   Siva said-
4.      O Siva Mahesani be pleased to hear the greatness of Rudraksha. I speak out of love for you from a desire for the benefit of the devotee of Siva.
5 - 7  O Mahesani formerly I had been performing penance for thousands of divine years. Although I had controlled it rigorously my mind was in flutter. Out of sport, I being self possessed just opened my eyes. O Goddess, from a desire of helping the worlds, drops of tears fell from my beautiful half closed eyes. From those tear drops there cropped up the Rudraksha Plants.
8      They became immobile. In order to bless the devotees they were given to the four varnas devoted to worship of Visnu.
20    O Parmesvari no other necklace or garland is observed in the world to be so auspicious and fruitful as the Rudraksha.
47    People of all varnas and Asramas even Women and Sudras can wear Rudraksa at the bidding of Siva. The Ascetics shall wear it with the Pranava.
62   Even the devotees of Visnu and other Dieties shall unhesitatingly wear the Rudraksa. Especially the devotee of Rudra shall wear Rudraksha always.
76   O Mahesani, Rudraksa with ten faces is Lord Janardana Himself. O Devasi by wearing it the devotee shall achieve the fulfillment of all desires.
86   Seeing a devotee with the garland of Rudraksas O Parvati, Siva, Visnu, devi, Ganapati, the Sun and all the gods are pleased.

Srimaddevibhagavat 11th Skand Chapter IV, Narayana said-
21   Ten Mukhi Rudraksa is Visnu and removes all the tears and troubles due from planets, evil powers and snakes.
Chapter V,God said-
22   Wearer of Rudraksa on hair tuft on the crown, in ear, in neck, in hand and in abdomen attains the status of Siva, Visnu and Brahma.

Mantramaharnava, Lord Siva said-
A Rudraksha with 10 Faces is General of an army and is also Visnu Himself. It sublimates the malefic effects of planets, evil powers and eliminates snakes.