How would a geologist identify an igneos rock as extrusive or intrusive?

Answer 1

You can look at the rock texture.If the crystals are Large enough to be visible with your naked eye without stressing it the the texture is likely to be either medium coarse grained or course grained which is an indication that it is Intrusive.The opposite is forExtrusive

Answer 2

Intrusive. Rocks with visible crystals of roughly the same size are said to have a phaneritic texture. The most common extrusive rock is basalt.

Answer 3

Extrusive igneous rock forms from molten rock cooling at the surface, so it is possible to directly observe its formation. Intrusive rock forms deep underground and can only be studied after it has formed.

Answer 4

A geologist forms a coarse grained rock with crystals arranged in rows what can the geologist infer about how this rock formed and what group it belongs to