in mineral crystal size.
Large crystals easily
seen, course –grained.
Very tiny crystals,
individual crystals cannot be seen without magnification, fine-grained.
igneous rock with
mixed texture with both large and small grained crystals.
large crystals in a
rock in the countryside prior to intrusion by magma
igneous rock – has forced its way into the surrounding country rock.
magma which has come
to the surface and cooled more rapidly, come from volcanoes
magma which flows out
on the surface of the earth.
very tiny droplets of
magma thrown into the air, often glass.
larger pieces of
volcanic rocks thrown into the air, cooled and formed as they fall.
name for all pyroclastic
rocks (those thrown into the air)
volcanic glass filled
with air pockets called vesicles.
from lava flows, very
tiny vesicles, very solid and dense. Comprised entirely of glass.
a liquid’s resistance
to flow. Resistance increases with an increase of silica. Mafic rocks have low
viscosity, felsic rocks have a high viscocity.