Earth science question, about crystal?

Question

what are the factors that control the shape of a well formed crystal?

Answer 1

1. Pressure

2. Internal Atom arrangement (this is a big one)

3. Cooling period (long- big crystal, short- small/no crystal)

4. Heat

Answer 2

The basic factor for forming of crystal is that the cooling period,If the cooling period  is longer then any type of mineral will be crystalised.About shape of crystal it is due to the arrangment of atom.e.g.Diamond : diamond is the best example of crystal the shape of diamond is due to arrangement of carbon atom in it.So the heat as well as pressure is also dominant in formation of well developed crystal.

Answer 3

Here's a google book search for your question.

http://books.google.com/books?id=mFx7rwD...

The answer is 2 to 3 pages up.