Unpopular opinion: a chat with a park ranger in Zion changed my mind about obsidian

I was hiking the Narrows trail last fall and got talking to a ranger at the visitor center... I always thought obsidian was just a cool, sharp black glass. But she said, "You know, most people fixate on the color, but the real story is in the flow lines and how fast it cooled." She showed me a piece with these tiny, almost invisible bands you could only see in the sun. It made me realize I'd been ignoring the formation process and just collecting pretty rocks. I've spent the past 6 months re-examining my whole collection with a hand lens. Anyone else have a basic rock fact that totally shifted how you look at specimens?

2 comments

2 Comments

mitchell.mark1mo ago

That ranger nailed it. I had the same thing happen with quartz. I just saw it as a clear crystal forever. Then a geologist friend pointed out all the different crystal habits and how the shape tells you about the space it grew in. Now a boring lump of milky quartz can be the most interesting thing in my box because of its story. It turns the whole hobby from just gathering stuff to actually reading the rocks.

ryan_flores1mo ago

Ever notice how that happens with almost everything once you learn how it's made?