Porphyritic
i thing becaUSE THEY ARE COOLED
gradual rise in the sea level
If a substance is cooled and solidified rapidly, generally amorphous material is obtained instead of crystals. In order to obtain good quality crystals, if is better that the substance solidifies slowly
When cooling, a precipitate will be formed as the solublity product decreases.
Igneous rock is formed from the cooling of magma or lava.
i thing becaUSE THEY ARE COOLED
gradual rise in the sea level
A crystal is a homogeneous solid substance that has a natural geometrically regular form. The crystals that form in slowly cooled magma produce large grains.
If a substance is cooled and solidified rapidly, generally amorphous material is obtained instead of crystals. In order to obtain good quality crystals, if is better that the substance solidifies slowly
Crystallisation
That it cooled very slowly.