Probably a pebble.
A rock can be gravel or any tiny pebble... so ya... it's a rock.
The gravel and sand filter out smaller particles from the water
No. Pebble-sized particles from a volcano are called lapilli. Ash is sand-sized or smaller.
Smaller than that, even; the size of a grain of rice, or smaller.
You would use a filter in this case a grate bigger than the the sand yet smaller than the gravel that you could probably buy at your neighborhood grocery store or online.
Pebble larger than clay
Pebbles, stones, gravel or sand. With some rock it would be shingle.
a pebble is smaller
Sand, gravel, shingle, pebble and cobble. There are more, but these are the ones I know, hope I helped Sand, gravel, shingle, pebble and cobble. There are more, but these are the ones I know, hope I helped
Well, one system says if a grain of sand is bigger than 2mm, it's a pebble, and a pebble bigger than 100 mm is a cobble, and a cobble bigger than 256 mm is a boulder, so you could use "pebble" for "gravel" I reckon.
Much smaller.
A rock can be gravel or any tiny pebble... so ya... it's a rock.
Cobble
The gravel and sand filter out smaller particles from the water
No. Pebble-sized particles from a volcano are called lapilli. Ash is sand-sized or smaller.
No. Ash consists of sand sized particles and smaller. Pebble sized particles are called lapilli.
Yes, sand has fine particals, gravel is much larger.