is a term usually used to refer to igneous rock grain size
. It means that the size of grains in the rock
are large enough to be distinguished with the unaided eye
as opposed to aphanitic
(which is too small to see with the naked eye). This texture
forms by slow cooling of magma deep underground in the plutonic
environment. It may also appear in, and be applied to metamorphic rocks
, with the same definition.