Question:

What is the Difference between Natural and Lab Created Gemstones?

The major difference is their origins or their "place of birth". Natural Gems are found in the ground through mining or panning processes. Lab Created Gems have there origins in a Laboratory and are grown under carefully controlled conditions to produce the exact color and clarity desired. 

Question :

Are Lab Created gems the same as Natural gems, Like Ruby, Sapphire or Emerald?

Yes!  They are the same exact material.  Ruby, Sapphire or Emerald.

They have the same specific gravity, MOHS hardness, and same molecular makeup as natural gems.

Question:

Why do natural gems cost more if they are the same?

The reason natural gemstones cost more is because of the inherent costs of mining for them.  There is a lot of labor costs that go in to mining for a gemstone.

Question:

Which is better ( Natural or Lab ) ?

That is a hard question to answer.  Natural stones are valued for there rarity while lab created gems are valued for the AAA pure quality.  I guess the choice is up to the buyer.  It all depends on the amount of money they are looking to spend and the quality of stone they desire.