Consider the definition of a mineral. Why would a synthetic ...

[jake]

Consider the definition of a mineral. Why would a synthetic gemstone fail this definition and not be considered a true mineral?
 
  What will be an ideal response?

Question 2

If there are over 100 elements on the periodic table of elements, it would stand to reason that there would be millions of ways these elements could combine to form minerals. However, there are only 4000 named minerals.
 
  Why might there be so few minerals on Earth when there are so many possible combinations?
  What will be an ideal response?

[cswans24]

Answer to Question 1

Answer: True minerals are naturally occurring, whereas synthetic gemstones are generated by artificial/ human-made processes.

Answer to Question 2

Answer: Not all the elements on the periodic table are equally abundant. Ninety percent of the Earth's total mass comes from O2, Fe, Mg, and Si.
- Oxygen = the only abundant element in the crust that is an anion.
- Silicon = prefers bonding with oxygen more than with anything else.
- Oxygen, on basis of volume, makes up a large percentage of the Earth's crust.