Rock flour

Rock flour is like super-duper fine dust made from rocks. It happens when big, icy glaciers slowly grind rocks together, like a giant rock-grinding machine! This tiny dust gets mixed with melting ice water, making the water look cloudy, like milk. That's why sometimes it's called 'glacial milk' because it comes from glaciers. It's so small, it can float in the water for a long time.

This special rock dust is born in cold places where glaciers live, like tall mountains or icy lands. As glaciers move, they scrape and crush the rocks underneath them. It's like a giant ice cream scoop digging into the ground and making tiny rock bits! Sometimes, people can also make rock flour by grinding rocks very, very finely, just like the glaciers do.

When this rock flour floats into rivers, it can change their color! Instead of clear water, you might see a river that looks grey, light brown, or even a milky white. If this colorful water flows into a lake, the lake can turn a beautiful turquoise or blue color. It’s like someone spilled a giant bottle of blue paint into the water!

You can see these amazing colorful lakes in places like Canada, New Zealand, and Norway. Lakes like Lake Louise in Canada or Lake Pukaki in New Zealand get their stunning colors from rock flour. The tiny rock bits in the water catch the sunlight and make the water look extra bright and colorful, especially when the sun shines just right.