About igneous rocks. What's the visible difference between volcanic and plutonic type....?

Question

All igneous rock comes in two types, volcanic and plutonic. They are identical in chemistry, and identical in mineralogy. Where do these respective rocks accumulate, what is the visible difference between them, how does that difference develop?

Answer 1

most visible difference is that they seem to be just friends- it develops from a desire for companionship.  or  is that platonic? i keep getting the two mixed up.

Answer 2

One of the observable differences is in the size of the crystals from intrusive and extrusive igneous rocks.  The intrusive rocks have a long time to cool under pressure so the formation of large crystals is possible.  The extrusive rocks do not contain large crystals because the rock cools too quickly.

Answer 3

Volcanic rocks, also known as extrusive igneous rocks, are created when magma is extruded onto earth's surface as lava. Plutonic or intrusive igneous rocks form when magma cools and crystallizes deep inside the earth. Extrusive rocks form from rapidly cooling magma (lava) and due to the quick crystallization, insufficient time is available for large crystals to form- hence these rocks have a fine texture or aphanitic texture (crystals too small to be seen by the naked eye). Intrusive rocks form from magma that cools slowly and this lends ample time for large crystals to form- hence intrusive igneous rocks have a coarse texture or phaneritic texture (crystals large enough too be seen with the naked eye).