I bought Mrs. MacQuaide a lab grown rock. 2ct. She loves it, and knows exactly what it is and where it came from. It' got a TON of fire in it. Very brilliant. Quite a few women have commented on how nice it looks, as in "GAWD what a ROCK!"
Not all women are suckers for marketing, some actually take other things in to consideration and gifts of jewelry are so low on the list as to barely carry weight. Perhaps you guys are light on the other factors and need the rock to convince your SOs. If my wife had needed a gift of a piece of jewelry to feel comfortable in our relationship it would not have lasted months let alone 20 years. Still no rock, still no need. If your lady needs a rock either she is insecure (that means you should know you are probably tying yourself to a high maintenance headache), or you are not showing her the love and respect she needs so she needs the rock as a substitute/proof.
There are whole societies of sensible women, Americans not generally included. I married a Norwegian. In Norway, at least back then, a simple gold band is worn on ring-finger, right hand, to indicate engagement and them switched to the left hand to indicate your married state. When most young people are starting out, spending a bundle for an engagement ring is a clear indication of lack of ability to think or excessive "herd following" mentality.
For those interested in a more in-depth treatment of the diamond cartel Edward Jay Epstein has his entire book on the subject online free: http://www.edwardjayepstein.com/diamond/prologue.htm Also online is his article on the topic that appreared in _The Atlantic_ in 1982: http://www.theatlantic.com/doc/198202/diamond
has not anything changed in 25 years since the article was published. has the diamond cartel weakened etc.?