This is a cracking good word. I’m not suggesting you try to pronounce it, but if you do, you may well make the sound that inspired the name in the first place.
But your tongue isn’t the only thing put under strain by this word. Lexical and even intellectual faculties can be challenged by the definitions and descriptions. Here’s the Oxford English Dictionary: “A form of aragonite, occurring as pisolites under strain, which decrepitates.” (Webster’s Third New International Dictionary has never heard of it.) If that’s Greek to you, the original description, in the Journal of the Chemical Society, explains: “When heated to low redness, the pisolites violently decrepitate, and detached scales are then observed to be partly transformed into calcite. . . . The violent decrepitation, on account of which the name ktypeite is given, shows that the pisolites must be in a state of considerable strain.”
You too, eh? A lot of us are in a state of considerable strain, and many of us are decrepit because of it. But decrepitation has just a slightly different sense here. If a house or a person is decrepit, that literally etymologically (though not necessarily actually, but probably) means it emits cracking sounds, like the walls of an old house or the knees of a no-longer-young guy. The Latin source is ultimately crepare, ‘rattle, rustle, crack, creak’. Decrepitation, however, is the noun for the shattering of minerals when heated, which typically involves a loud cracking sound.
Which means that Alfred Lacroix heated up some samples of this mineral, which he found in Carlsbad, Bohemia, and they went “crack!” and shattered. Well, not the whole piece at once; just one or more of the pisolites. What are pisolites? Imagine one of those jawbreaker candies with concentric layers. Now imagine that all the layers are grey. And that actually they’re sedimentary rock. And that they conglomerate. And that if you hold one over a lit burner, it makes a sharp noise and, as mentioned, shatters. Leaving a hole. Oh, yes, that’s another point of strain: if you have anything on the order of trypophobia – which is to say, if things with lots of small holes in them creep you out – don’t look up any pictures of ktypeite. Eek, so creepy.
But does this mean that Lacroix spent some jolly time exploding bits of this rock like some gleeful adolescent with a sheet of bubble wrap and then transcribed the sound they made as “ktype”? (The ite is a standard mineral suffix.) Or perhaps scrawled something and then added a note to his secretary, “K, type that”? Not quite. As scientists so often do, he turned to the Greeks. And he found this charming agglomeration of phonemes in the word κτύπος (‘crash, bang’).
Alas, English (or anyway its speakers) does not tolerate a /kt/ onset. The ktype in this word is expected to be said like “tippa” – though “tippa-ite” (/ˈtɪpəʌɪt/) is itself about as awkward as trying to step around some doggie doo on a ledge. And it has a hole in it where the /k/ should be.
But it’s OK. You don’t need to turn up the heat on yourself to say this word. You can just set it there on the page, comfortable in the knowledge that its object is probably just aragonite anyway, and for the moment let the reader take on the strain – and perhaps hope they don’t crack while you’re around.