Rudrakshas from Nepal are between 20 and 35 mm (0.79 and 1.38 in) and those from Indonesia are between 5 and 25 mm (0.20 and 0.98 in). Stones typically have between 1 and 21 faces, although most have between 4 and 6 faces. Rudraksha stones are described as having a number of facets or "faces" ( mukhi) which are separated by a line or cleft along the stone. Types of rudraksha stones ĥ-faced ( pañcamukhi) rudraksha stone with the lines delineating its faces labelled They also contain rudrakine, an alkaloid which had been discovered in rudraksha fruit in 1979. Rudraksha fruits contain alkaloids, flavonoids, tannins, steroids, triterpenes, carbohydrates, and cardiac glycosides. Rudraksha beads are sometimes called "blueberry beads" in reference to the blue colour of the fruit. The blue colour is not derived from a pigment but is due to structural colouration. When the fruit is fully ripe, the stones are covered with a blue outer fleshy husk of inedible fruit. The pyrena of the fruit, commonly called the "pit" or "stone", is typically divided into multiple segments by seed-bearing locules. These fruits are commonly called " rudraksha fruit", but are also known as amritphala (fruits of ambrosia). It yields between 1,000 and 2,000 fruits annually. The rudraksha tree starts bearing drupes (fruit) in three to four years from germination. Ripe rudraksha fruits displaying their typical blue colour 'face') or locules, and rare or unique stones are highly prized and valued. Various meanings and interpretations are attributed to rudraksha stones with different numbers of "faces" ( Sanskrit: मुख, romanized: mukha, lit. The stones are primarily sourced from India, Indonesia, and Nepal for jewellery and malas ( garlands) they are valued similarly to semi-precious stones. The stones are associated with the Hindu deity Shiva and are commonly worn for protection and for chanting mantras such as Om Namah Shivaya ( Sanskrit: ॐ नमः शिवाय Om Namaḥ Śivāya). The rudraksha stones are produced by several species of large, evergreen, broad-leaved tree in the genus Elaeocarpus, the principal species of which is Elaeocarpus ganitrus. When they are ripe, rudraksha stones are covered by an inedible blue outer fruit so they are sometimes called "blueberry beads". Rudraksha ( IAST: rudrākṣa) refers to a stonefruit, the dried stones of which are used as prayer beads by Hindus (especially Shaivas), as well as by Buddhists, Sikhs, and Muslims. Rudraksha beads are the dried stones of the fruit of the Elaeocarpus ganitrus tree