Natural diamonds (which is what I presume you meant by “normal”) require the removal and processing of a ton or more of kimberlite rock in order to extract one carat (1/5gm) of diamonds. It is dangerous, and environmentally destructive work. Lab created diamonds, though currently limited to cut stones of five carats or less, do little to disturbe the planet save for the large amount of energy required in the two established manufacturing processes in place. And even with this, I believe that synthetic diamonds come out on top. Unfortunately, because of the expense of the sophisticated equipment required to synthesize gem quality diamond, and the high level of experience and skill required to properly cut ANY diamond, the prices of cut synthetic gems remains inordinately high.