I took my first geology classes in the mid 1990’s. That was where I first learned about the mineral sphene, a calcium-titanium phosphate common in a wide variety of rocks. I first saw it in my Introductory Lab, and then later on in Mineralogy I started to learn to identify it in both hand sample and thin section. Sphene is one of those fantastic minerals that actually has features that make it easy to identify. In think section, or as grains, it is often a  honey brown or greenish color, for example. Most distinctive, however, is its shape. It often forms little wedges, which in thin section look like little diamonds. Hence the name! This is one of those great instances where the name of the mineral actually relates to one of its identifiable features. Sphene comes from the greek word for wedge, which is pronounced “sfeena.” Well that is handy!

But even then I sensed something wrong, a wind from the east, as Gimli (who likely would have been a geologist if it were not for Sauron) would say. Check it out, here is a picture of the entry for sphene in my copy of Deer, Howie, and Zussman.

photoAll that great information you expect from DHZ, density, hardness, all of the optical properties…but what’s that? In parentheses, after sphene, is written “titanite.”

I continued to call this mineral sphene, but I slowly realized that the word titanite was taking over. First I saw papers that would write “sphene (titanite),” and now the literature is dominated by titanite. What happened to sphene?

Turns out the Commission on New Minerals and Mineral Names “discredited” the name sphene in 1982, and has promoted the less-poetic “titanite” ever since. Credit to my professors for sticking to their guns, but by the time I learned about the little honey-brown wedges it has been a dozen or so years since the name had been discredited.

Now this bugs me. It isn’t logical, and is likely just a rant, but I dislike the name titanite, immensely. Why you don’t ask? Let me tell you anyways.

1. Sphene makes sense. It is descriptive and sounds nice. It means wedge. That is the fastest way to identify the mineral, easy-peasy-lemon-squeezy. Perhaps that is qualitiative and subjective, but this is my blog so pppppffffffttttttbbb!

2. Titanite sounds like a mineral made up in a science fiction movie. Like unobtanium. Not a poetic made-up material like mithril, but a made-up word from some third-rate science fiction movie. Maybe a mineral named by a soulless robot petrologist who hates words that start with 3 consonants and wants to annoy me.

3. But here’s the big one. I would understand calling it titanite if it was loaded with titanium, or was the most titanium-rich mineral, or was even the most important source of titanium ore. BUT IT ISN’T! One lousy Ti atom stuck in with Ca, Si, and 4 O’s. It would be like calling apatite “phosphite.” If anything should be called titanite it should be rutile! Rutile is 60% Ti by weight, blowing lowly “titanite” out of the water! Or Ilmenite for fuchsite sake! What not change those names? Ilmenite and rutile are even titanium ore minerals, unlike sphene.

4. And finally, the commission discredited the name sphene? Really? Why, because it was so appropriate and descriptive? Because it was easy to remember once you were told about the greek root? Because it is a handy scrabble word? I’d like to know more about this decision, quite honestly. My “research”, which consisted of me googling things after a few beers, turned up little, and it was well before my time. Perhaps there was a great reason, but I can’t seem to find a record of it. Email me if you know!

I’ve yet to publish anything on sphene, but if I do I hope to take a stand. Maybe the journal won’t allow it. Maybe my co-authors will roll their eyes when I begin my rant. But for now, LONG LIVE SPHENE!!!!!

This entry was posted in Rants, Uncategorized. Bookmark the permalink.

1 Response to LONG LIVE SPHENE!

  1. Pingback: Geology and Scrabble | Apparent Dip

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