Hey, Who’s Up for Sniffing Some Elemental Flourine?

This guy, apparently.

Via Katharine Sanderson at Nature.com:

Fluorine gas is so reactive that any naturally-occurring whiffs cannot exist for more than a few fleeting seconds. At least, that has been the conventional wisdom for more than a century.

Now, chemists have proved that a smelly rock is the only known place on Earth where fluorine exists in its elemental form, F₂.

The rock is antozonite, a calcium fluoride (fluorite) mineral that is dark violet or even black in colour, also known as fetid fluorite or stinkspar. Needless to say, this rock stinks. The pungent smell is given off when antozonite is crushed, and chemists and mineralogists have argued over the origin of the stench since the early nineteenth century.

[Dr. Florian Kraus’s] first task was to smell the crushed rock — and he immediately recognized the stench: “A fluorine chemist knows at once how fluorine smells,” he says.

OK, but that’s not so helpful to the rest of us.

From the opening lines of the paper:

Elemental fluorine, F₂, is the most reactive chemical element. Great experimental skill and special equipment are necessary to handle it safely.

So Kraus does what any rational scientist would do . . . he inhales some!

We compared the smell of crushed “antozonite” directly with authentic F₂ gas and unambiguously confirmed that the odor of the mineral corresponds to F₂. The smell of F₂ is decisively different from that of O₃, Cl₂, HOF, HF, OF₂, and XeF₂, which were also smelled in direct comparison. [Dude!—Ed.]

We look forward to muddling some antozonite into our next mojito. So what if there is a little uranium or thorium in it? That’s what gives you the five-hour energy!

The article discussed here is "Occurrence of difluorine F₂ in nature—in situ proof and quantification by NMR spectroscopy,” by Jörn Schmedt auf der Günne, Martin Mangstl, and Florian Kraus, which appeared in Angewandte Chemie International Edition, July 4, 2012.