Why are crystals bigger when liquid rock cools slowly?

Answer 1

Crystals being cooled rapidly means a very high temperature gradient. When the temperature gradient is very high the number of nucleation sights is very high.(To visualize, think of cold water being poured into a very hot pan--it forms a large number of bubbles). Thus crystallization starts at many such nucleation sites and we have smaller crystals as the overall volume is constant.

But when the temperature gradient is not high, there aint enough nucleation sights and solidification (nucleation) occurs at far fewer sites. Thus assuming constant total volume in either case, the crystals are smaller.

Answer 2

When liquid rock cools slowly, the molecules have more time to arrange themselves into an ordered crystalline structure, leading to larger crystals forming. Slower cooling allows for more diffusion of atoms, resulting in the growth of fewer but larger crystals.

Answer 3

Yes. It is a characteristic of intrusive igneous rock that has solidified below the surface, like granite.

Answer 4

the crystals begin to get larger

Answer 5

granite

Answer 6

yes