A mala traditionally carries a hundred and eight beads plus one larger guru bead marking the start and end of the count, and each bead is knotted individually along the cord rather than strung loose, both to stop them clacking together and so a single break does not scatter the whole strand.
Material, real and counterfeit
Rudraksha seeds, from the Elaeocarpus tree, are the standard material for Shaiva practice and a long running source of fraud, since genuine multi faced seeds are rare and expensive and the market is full of carved or dyed substitutes sold as the real thing. Bodhi seed is preferred in Buddhist practice for its association with the tree of the Buddha's awakening, sandalwood is common across all three traditions for its scent, and rock crystal or bone, traditionally yak bone in Tibetan sourcing, appear in more specialized tantric practice.
Who strings them, and what happens to a broken one
Lay artisans and monastic workshops both produce malas, and in Tibetan Buddhist practice a completed mala is often brought to a lama to be blessed or empowered before regular use, a step that matters more to the practitioner than the raw material does. A broken mala is restrung rather than thrown away, since the beads themselves, not the cord, are considered to carry the accumulated use, and a mala worn out beyond repair is more often kept or given away than discarded.