Its an insider's journal paper so they gloss over what zircons are although they're the whole point of the paper. The chemistry of zircons is pretty cool. A n

Its an insider's journal paper so they gloss over what zircons are although they're the whole point of the paper. The chemistry of zircons is pretty cool. A non-technical terrible analogy is they're like nearly indestructible test tubes that bottle up whatever contaminants are in the area when they initially crystallized and then they sit there for eternity or until lava melts them (and some lavas aren't hot enough to melt them, whoa!). So various natural variations in Hf isotopes by location are bottled up by zircons, and when melted into ancient glass the glass liquifies at a half or third the temp required to liquify zircon crystals, so they sit there with evidence of where the materials came from bottled up for all eternity. Zircon also shows up in radwaste schemes. Despite mother nature and humanities best efforts we generally haven't destroyed zircons over centuries, so it seems a useful strategy to bottle up radwaste in giant zircon crystals. Weird fact, most zircons are stable at boiling iron temperature. Note I wrote boiling, not melting iron. Liquid tungsten is hot enough, sure, but not mere liquid iron. Its a pity zircons are structurally useless. Of course it would be a recycling nightmare if they were industrially useful for bulk structures and components. Interesting sci fi aspect, all the chemists I've talked to are certain that Pierson's Puppeteer General Products space ship hulls were based on the idea of industrial zircons as a structural material although in one story those hulls were proposed to be a carbon fiber analog of zircons or something like that. A "zircon polymer", should such a magical material exist, would make an interesting structural material when threads of it were knitted into 3d shapes.