Saturday, June 25, 2011

Sphene

Is my favorite geological word. Or rather, my favorite formerly geologic word. From a lawyeristic point of view, it hasn’t been a geologic word since 1982, despite having been the preferred name for Ca TiSiO5 for the 4,566,999,971 years prior to that date. These days, you don’t sphene spoken of much, as most of us who mutter it are busy yelling at the young whippersnappers to get off our psilophytopsid lawns. However, it has not totally disappeared from the scientific literature, despite the best efforts of the IMA to discredit it. And the materials scientists might actually still prefer sphene (God belss them).

Of course, most mineralogists these days dutifully go along with the official name (the “T-word”, since despite my use of cunt, nigger, and fuck in this blog, I do draw a line at really offensive words, like t*&#%ite). And why shouldn't they use the official name? They are just following orders. But there are still a few cowboy rock smashers around who got into this field because we were never particularly good at following the rules. And while I am not so old-fashioned as to refer to element 41 as columbium, I do prefer sphene.

The T-word is a stupid name. The mineral was known (and called sphene) long before the element titanium was discovered. The name is derived from the greek word for wedge, whoich describes the shape perfectly. In contrast, commercial titanium is mined from ilemite or rutile, not sphene. And the element was originally discovered (independently) by processing ilmenite (in the UK) and rutile (in Germany) in the 1790’s.

Sphene has a domain name.
The t-word does not.
Sphene is pretty.

Finally, any sphene used in geochronology was almost certainly sphene when it crystallized, and only morphed into the T-word at a very late stage in its evolution. Fortunately, the sphene/T-word transformation does not upset the U-Pb isotopic system, so that dating of sphene is still possible today.

3 comments:

Silver Fox said...

We still use sphene on our way--post-1982 logging program (someone else doesn't like the T-word).

And biotite is out, also??!! Or is that just mindat at work?

C W Magee said...

The list is here.

Silver Fox said...

Thanks, Chuck, I'll append the list to my recent report.