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.