I saw the word geode in a poem and went on a dictionary journey.

Fissures and smaller cavities in rocks are called vugs. They fill with deposits of minerals or crystals, which can be corrosive and hollow out or fill stones such as limestone. A geode is a specialized vug. If a geode is solid all the way through it's called a nodule.

It's breathtaking and terrifying how suddenly and completely subjective language becomes with words like fissure and cavity. They're kind of the same thing, but then why do we have the two words, so they're not the same thing, so why? If you know these words you know that fissures and cavities both can form from an overlapping variety of processes (pressure, contraction & expansion, a sharp blow) so this is not a point of differentiation. How I think of it is that a fissure is small, maybe even not open, like a visible crack. A cavity is an opening. But obviously, by dint of being visible at all, a fissure is an opening, it's just too narrow to see with the naked eye. If I could electron-microscope-see then a fissure would look like the grand canyon. I can't see this way, and I'm not tiny, so when it comes to language about it the place where understanding is in play is at what point does a fissure open enough that it is no longer a fissure but a cavity. It would vary from person to person, a judgment call. But this variation in fissure/cavity degrees and resultant play in the language doesn't seem to matter. I use them as synonyms, I know they are not synonyms, I am still living and breathing. So the two words exist in order to express great specificity (and families of adjectives exist for both words for even further specificity) that I rarely or never need to express.

The size we human creatures are and our dexterity and our sensory abilities, these three qualities/conditions crammed into one thing determines the range of how we interact with our environment and the amount of nouns and their intussusceptions into granularity, and the adjectives we append to them. If we could electron microscope see (or touch or feel or smell or hear) then we would need realms more words. Entire concentric dictionary shells around the dictionary we know.

It's interesting because a clast is a rock fragment. But isn't it just as legitimate, when you break a rock into two clasts, to also or instead call them two rocks? A clast must be smallish, it comes from the Greek word for to break or to destroy. Hence an iconoclast is someone who destroys religious imagery or, in our secular age, someone who goes always against the grain. But shards are busted up rocks really small. It would be useful to have a geologist differentiate clast from shard. Like, if you break a rock into chunks, they're clasts, but if you smash the rock to utter bits then maybe they're shards? Isn't this just another instance of how our specificity vocabularies really only need to go as far as our relative sensory scale to the things we're talking about? And frankly a geologist's explication might not be useful at all to me, this might be why I don't know this differentiation in the first place, I've no stake in needing a differentiation other than curiosity. Or rather avoiding the anxiety that comes from a curiosity about things essentially uncertain (i.e. language and fucking everything else when you really look at it).

So by now it feels like the dictionaries are piling up on my chest.

Another thing that became apparent is how my usage and understanding of rock was kind of off. This isn't a word we'd think of as technical language or specificity vocabulary. In fact it's in one of those early layers of nouns that toddlers learn, before they're even forming anything close to a sentence. When the word's utterance is comparable to pointing at the thing. I taught Sadie this word last weekend, crouching in a gravel lot. But it has some specificity that I didn't realize because I never need it, nor does she. Though we easily could.

Words like stone and mineral I use as synonyms, overlapping or simply being the same as rock. But it seems that rocks and stones are things that are made of minerals. And that rocks can be made of stone. So a rock can be made of limestone, and limestone comprises organic calcium minerals like crushed shells. But I pretty much use them all as the same word, and that works out fine for me. Is this a problem? When might it be a problem?

A word like breccia really brings this out. It's a rock that forms when a bunch of clasts or rocks or shards and so forth are lying there (maybe from a rock collapse) and they get all filled in with sand maybe mixed into a concrete-like slurry with water, forming what's called a matrix, like a cross-section of a snickers bar. And all this hardens into completely solid and pressure makes it really hard so it becomes, so far as our interactions with it goes, one thing. Marble is said to be brecciated (nice adjectival form there). A rock in its own right, but comprising other rocks and things. Different rocks tumble down into a pile and become a single, different-again rock. So what does rock mean again? It gets subjective, like if I was a superman and could crumble marble in my hand like a loose dirt clod I wouldn't consider it a rock, so I would maybe think of it not as a single rock but as a clump of lots of other rocks and other stuff. And I probably wouldn't have the word breccia in my language. Or would I, maybe for some other reason? Description?

Words just fall through other words, though we still have to get up in the morning and live all day. We've no choice but to let them fall, or be two mirrors facing each other. If you are comfortable enough in your momentary situation to not need to ask "how big/small am I compared to it?" or "how do I open this object/situation as an idea or system to my understanding?" then you should be fine. But how often are we fine like this?

Anyway, the Giant's Causeway in Ireland is very cool. It's what's on the cover of Led Zeppelin's Houses of the Holy, remember?