iron sand sword rubble

By the time Mikoto’s body stiffened, the flying fish had already run up onto the beach. A
large amount of sand was knocked up into the air and the flying fish continued further
on. As it scraped along the asphalt pathway, sparks flew and it finally struck the private
showers for swimmers.
A portion of the smashed wall flew spinning through the air. The giant piece of rubble
was over three meters long and it passed by over the sightseers heads.
“!!”
Immediately afterwards, light sparked from Mikoto’s bangs.
The white sand at her feet swelled up. No, technically it was the iron sand mixed in with
the white sand. That iron sand formed a black sword which shot a few dozen meters into
the air with snake-like movements where it mercilessly blew away the falling piece of
rubble.

- Toaru Kagaku no Railgun SS1, Chapter 1