Rudraksha beads can be worn by anyone. There are different Rudraksh for different purpose and you need to pick the right one.
On the contrary, Rudra ( referred to Shiva ) and aksh ( tear drop ) , the tears of lord shiva. Shiva is the name of Supremesoul. He is called Allah and in other names. So Shiva is not related to any particular religion. He is the almighty God And his name is Shiva.
Regardless of the fact that Hindus were the old religion and started using it early, and discovered them earlier. So there are so much of references in old books.