Norbu in Tibetan means jewel. In a culture where the spiritual dominates the material, Norbu refers primarily to the Three Jewels; the Buddha, Dharma and Sangha whose power can free sentient beings from the clutches of cyclic existence and its never ending rebirths.
This concept does not preclude the appreciations for gems, and turquoise, coral, pearls, and the uniquely Tibetan agate stone called Dzi, were widely used and valued In the Tibetan worldly realm. Bright blue turquoise was considered most precious. Found randomly and considered a gift from the gods, it was also traded from Iran, known for its high-quality stones. Corals came along the Silk Road from Italy, and many of the pieces used in Tibet were there for hundreds of years, and continue to be imported using contemporary routes. Pearls, mostly river pearls, were traded or native, found in rivers. Dzis, oblong agates pierced with a hole and decorated with patterns of circles referred to as eyes, are now believed to have been the work of the early inhabitants of the Tibetan Plateau, several thousand years back. Found buried in random places, they were said to become visible only by the will of the local deity they belonged to, and who wished to gift them to humans.
Though the gems found in Tibet were mostly found or traded, the stories from the Avadhana and Jataka tales, which recount the past lives of the Buddha, tell of merchants who went out to sea to seek their fortunes and extract jewels from the ocean. They had to barter with the immensely wealthy Nagas, or serpent gods, who would dispense the precious stones to them if inclined to do so. They were subject to their whims and to the wrath of the sea monsters, who could turn over their ships and gobble them up. Historically, Indian merchants did travel as far as Sumatra in search of pearls and other valuables, and their findings from these distant lands made legend, though many never returned.
Jewels were not only worn by men and women as necklaces, pendants, hair ornaments, rings and earrings, they were also incrusted into silver and gold ritual objects and offered to statues and stupas as acts of merit, that of giving up material goods for spiritual gain.