Few beads are surrounded by as much mystery and myth as the dZi bead (say zee).
These etched agates are found in Tibet, Bhutan, Ladakh, and Nepal, and
are believed to be about two thousand years old. Many legends accompany
the beads- that they were not made by man but created by the gods (by
lightning strikes, or sometimes, goats), that they bring luck and ward
off evil, that they protect the wearer from physical harm by taking the
abuse upon themselves, and that the bead itself will choose its' owner
and will not stay with an unlucky person. (To which we can only add,
certainly a person is unlucky who loses a dZi at today's prices).
Origins & Facts:
While possibly not actually Tibetan in origin, Tibetans and other Buddhist cultures (such as those of Ladakh and Nepal), have embraced these beads and imbued them with mystery and belief. As fascinating as the cultures are that surround these beads, perhaps the most notable feature is the almost complete absence of actual facts. What we do know is; that they are found in the Himalayan region and span from just one thousand years ago to possibly as old as four thousand years; it is certain they predate Buddhism by quite a bit; and it seems likely that they were made by the Bonpo people (but ancient beads have also been found archeologically very far afield from Tibet).
Notwithstanding the above, the dZi bead has come to be commonly accepted as a 'Tibetan' bead, and Tibetans have become the world's 'experts'' on these fascinating beads. Tibetans evaluate the purity of a bead by many criteria, such as good contrast, desirable patterning, symmetrical shape and strong color.
Chung or 'lesser' dZi beads refer to natural or created banded agates without eyes, these are also much collected. dZi are more specifically, bleached, doped, masked and etched from carnelian agate. People have been creating beads in this fashion for many thousands of years across many cultures.
Ancient dZi vs. 'Real' dZi:
In the last 20 years 'new' dZi beads are being made in China and Taiwan. These are what I consider to be 'real' etched agates, made in (probably) much the same way as the ancient dZi beads. Though I feel these are 'true' dZi beads (as opposed to mock dZi's made of bone, glass or resin) and see them as desirable and collectible for what they are, they are nowhere near as valuable as ancient dZi. Tiger Tiger will never misrepresent these as being anything other than a nicely made new bead.
There are many, many people online selling these new beads with false claims of age. There seems to be thriving culture of unknowable or fantasy 'periods' for dZi beads (~how old is a rock?). Ebay in particular abounds with people selling new beads with outrageous claims. Many of these beads come with 'certificates of authenticity'.
The problem is obvious: There is no 'oversight committee' that can guarantee at least a modicum of integrity or expertise, such as the Gemological Institute of America (or AGS, AGL, EGL, IGI, etc.) provides for those buying diamonds and other gemstones, and every seller therefore provides their own 'certificate' (no doubt your 12 year old can generate a similar looking document in twenty minutes or so).
I've seen many online 'guides' for how to tell a real ancient bead from a new bead, but I believe the best way to learn about dZi beads is to handle them. Still, there are ways that the online buyer can can at least tell the real sellers, from the charlatans. Common sense can substitute for expertise in many cases: