Zi beads are not "etched"—as this is a mistaken idea from early archaeology. It is better to refer to this as "chemical decoration."
The results of chemical decoration are typically pale—ranging from quite white to "ivory" or creamy tan colors. Nevertheless, there are certainly other results.
The process(es), devised at 2,500 BCE, have been exploited for a very long time. Principally in India, but elsewhere as well. Particularly Burma. Given a long period, and different industries, there were probably variations in the formulas that were exploited—yielding different results. Among the first Tircul beads from Burma, that I documented in 1988, I noted several variations in line colors—including yellow, orange, and dark tan.
Discussions of the technology of Tibetan zi beads (that I think were probably made in India) began in 1982, with the publication of the Ebbinghouse and Winston article for Ornament; followed by a short series of dialogues between Ebbinghouse and myself. These dialogues were cited in The History of Beads (Dubin 1987). It is from reading these passages (and possibly consulting the literature we all cite) that Taiwanese beadmakers got the idea of making agate reproductions of zi beads—that first appeared in the marketplace in 1992.
Since the early 1990s, Taiwanese and Chinese reproduction zi beads have become big business, with multiples of factories cranking-out millions of beads. And there is considerable variety—as well as many editions that are frankly inauthentic and just made-up.
Your bead is a recent reproduction zi. It has tan lines. It is certainly not unique nor unusual, though perhaps you have not seen similar beads before. Jamey
The beads are not mine I copied the images from Baidu.
I'm sure you are correct about the bead that was shown.
It doesn't have the characters of ancient beads.
Happy new year to you .
Saw these magnified images on Baidu of these images of some beads surfaces.
Interesting circular cracks .
Are these dings Hertzian cracks as referred to in the article by Allison Carter.