Not really sure if this is the right place for this, but it involves Marriage so...
First a little information for those who aren't up to date on this stuff: The process of making diamonds in a lab has been more or less commericially mastered. We can do it repetitively and the Diamonds made in labs are actually of higher quality than those you would find in the earth. This is not the same thing as Cubic Zirconia or any of the other fake varieties of Diamonds available on the market, their chemical composition is exactly the same as real diamonds and the only way to tell the difference is with electron microscopes since the molecular structure of a synthetic diamond will have far less microsopic flaws than a natural one. Oh and synthetics are Cheaper than naturals by far.
Natural Diamonds on the other hand, mostly come from African slave labor, which often results in thousands of deaths per year (many of which are children), and the market supply is strictly controlled to artificially inflate the prices. On top of that many of the heads of the Company Debeers (The worlds largest diamon company) are not even allowed to set foot in many 1st world countries because of illegal practices they have been involved in.
So if I were considering asking a woman to marry me would I be morally obligated to purchase a synthetic diamond engagement ring (assumig of course that I would be following the tradition of using a diamond ring at all)?