|Wah Chang tag, hexagonal.
Wah Chang is a major refiner of niobium, zirconium, and other specialized metals. For a long time they had these little zirconium tags which they would send you, if you were contemplating using zirconium in some industrial application. They idea was you could hang it in whatever vat of horrible chemicals you were interested in processing, and find out if it could stand up to them. If it came out OK, maybe you would place an order for a ton of zirconium.
Unfortunately, they don't have them anymore! And even if they did, they wouldn't give you one just for asking, unless they really thought you might be a potential customer, not just a mooching element collector. So I had to get mine off eBay for really rather more money than it should have cost.
It's amusing to note that while it's stamped "corrosion resistant" right on the tag, the tag is in fact quite visibly corroded, or at least discolored from tarnishing. Or, it might be that it was intentionally anodized, as they are said to have done with some tokens of this sort (according to Sheryl in the marketing department).
Source: eBay seller heruur
Contributor: Theodore Gray
Acquired: 3 June, 2003