What is one way that polymorph minerals, such as ...

[kwoodring]

What is one way that polymorph minerals, such as aluminum-silicates, change from one form to another?
 
  A) Temperature and pressure conditions change with depth, causing metamorphosis.
  B) They break up and change form during resedimentation.
  C) Other minerals join the polymorphs during contact with igneous intrusions.
  D) Fluid metamorphosis allows other elements to fit between the main mineral bonds.

Question 2

Why don't diamonds turn back to graphite once they reach Earth's surface?
 
  A) Diamonds are too hard to undergo reactions.
  B) Temperatures need to be lower than those found on Earth.
  C) There is not enough heat on the surface of the earth to drive the reverse reactions.
  D) Humans harvest diamonds before they can turn back to graphite.

[tkempin]

Answer to Question 1

Answer: A

Answer to Question 2

Answer: C