S
24

The mystery of the shiny pebbles in my creek bed finally makes sense

In my experience, I kept seeing these sparkly bits in the water and had no clue what they were. Your mileage may vary, but I posted a photo on a geology forum to ask. Take this with a grain of salt, but folks there said it was mica washing out from old rock layers. Now I understand that heavy rain exposes more of it. It's cool to see a bit of earth science happening right outside.
3 comments

Log in to join the discussion

Log In
3 Comments
jenny_grant82
Yeah, I've noticed the same thing along the riverbank near me. It's all these little glittery flecks in the gravel after a storm. Really catches the light. Felt good to finally have a name for it, mica, after wondering for ages.
5
skyler_reed
Ever consider that mica might signal pollution instead of pretty rocks? It doesn't dissolve, so storms just move it from old mining sites upstream. That glitter could be waste from decades ago, not natural geology. I've seen spots where the mica layer is thick from industrial runoff. It's worth looking into local history for mine locations. Changes how you view that sparkle after rain.
6
the_john
the_john10h ago
Actually that pollution take seems way too alarmist. Most mica is totally natural and breaks down from granite over centuries. Storms just uncover what was already there in the bedrock. Sure, old mines exist, but to assume every shiny spot is industrial waste is a stretch. Nature makes glittery stuff too, you know. It feels like some people just want to ruin nice things by overthinking them. Let a pretty rock be a pretty rock sometimes.
2