Igeneous rocks are classified based upon their mineral composition and?

And by texture or grain size

The answer is by surface or grain measure

Explanation:

Molten shake, or magmatic shake, is one of the three fundamental shake types, the others being sedimentary and transformative. Volcanic shake is framed through the cooling and hardening of magma or magma. The magma can be gotten from incomplete melts of existing rocks in either a planet's mantle or crust. Examples of nosy volcanic rocks are diorite, gabbro, stone, pegmatite, and peridotite. Extrusive volcanic rocks emit onto the surface, where they cool rapidly to frame little precious stones