Sand under bricks

At the side of my house we have some bricks and they sunk down abit, so removed them and checked for roots as there's a little tree and thought it disturbed it, it's fine.

When putting them back we had to put more under bricks to make it level, but had to stop as we need some more.

What's the sand called? It's like sand but has tiny amounts of stone almost like shavings.

If anyone can provide a link of what I need that'll be great, only need a small bag

Thanks

Sharp sand, any builders or DIY store

That's the stuff!thanks