Rock.
no
Shale is a sedimentary rock that typically has the smallest grain size due to its fine-grained and compacted nature.
A grain can be a tiny piece of rock, yes. A grain can also be a grain of salt, meaning one 'pellet' of salt.
Sandstone is the classification of rock composed of small rounded rock particles, usually quartz in nature.
The smallest rock in our solar system is nothing but asteroids.
An allochem is a grain of rock in a carbonate rock.
The smallest thing you could imagine - a dust grain, a molecule, an atom, a quark.
the size of a grain of rice
Not even close.
the grain of zircon and it is the width of a human hair
Marble is has no grain so it is classified as a glassy rock.
1.Grain Size 2.Grain Shape 3.Grain Pattern